You can find directions for modifying graphics in a number of places. First; check your carrier's Web site for instructions. You may also find directions on the Web site of your phone's manufacturer or in the user manual that came with your phone. Lastly, some of the Web sites where you can download graphics provide directions for modifying graphics on many different models of cell phones.

Operator Logos:

An operator logo is the logo of your cellular carrier. When you purchased your phone from your carrier, the phone was preprogrammed to display the carrier's logo when you start it up and whenever it makes a connection to the network.

On some newer phones, you can modify the operator logo and display another graphic in its place. When you replace the operator logo with a custom graphic, your phone will display that graphic whenever it would otherwise display the operator logo.

Caller Line Icons:

Newer phones support a feature called caller line icons (CLIs), essentially a graphical caller-ID feature. Load a graphic on your phone and associate it with a specific number or person in your contact list and your phone will display that graphic whenever that person calls. It's a cool feature; unfortunately, it isn't available on many phones yet, although you will find it on newer models.

On some phones, you can associate CLIs to specific groups of callers, in which case they are referred to as group graphics. You create a group (friends, work, and family), load a representative graphic, and then assign individuals to the group. When one of them calls, the graphic for that group is displayed.

Wallpaper and Screen Savers:

On some new phones with larger color displays, you can load customized wallpaper and even screen savers. Like operator logos and CLIs, this ability is dependent on the phone you have and your service.

Connectivity:

There is a lot of variation in the connectivity features available on cell phones. Some let you download a new graphic from the Web, while others let you connect using an IR port or data cable and download the graphic directly from your computer.

Downloading directly from your computer has its advantages. There are no airtime charges. You can even create cell phone graphics on your computer to your heart's content.

When you place a call on a POTS phone, the phone converts your voice to an electrical signal and transmits it over wires to your local telephone exchange. The exchange routes the call to its final destination over the phone company's network. For the most part, the call never leaves the network, except perhaps in cases where you call a cell phone from a landline, or when your phone company routes a long distance call through a satellite.

Mobile phones are commonly called eel/ phones because of the basic design of the network that they operate within. In a mobile network, a number of transceiver sites are arranged so that their signals or coverage areas overlap. A cell is the name given to the coverage area of a particular transceiver site, or cell tower .
The cell towers in a particular area link together through a central mobile telephone switching office (MTSO). Each MTSO authenticates and routes calls between transceivers in its service area, and handles billing. The software that handles calls at an MTSO is incredibly sophisticated. The MTSO also connects to the conventional telephone network and routes calls between cell phones and POTS phones

While the technology differs from carrier to carrier, the same general thing happens when you place a call with your mobile phone. When you turn your phone on, it notifies the network and authenticates itself. Authentication usually consists of the phone transmitting several pieces of information to identify itself and your account. One of these pieces of information is the electronic serial number (ESN).

Manufacturers encode the ESN on a chip within the phone. The other piece of information is the mobile identification number (MIN). The MIN is your cell phone's area code and phone number. Depending on the carrier and the underlying network, there may be more codes used to authenticate your phone or establish calls.

When your phone transmits this data, the closest cell tower receives it and routes it to the MTSO. Once the MTSO verifies your phone, it then accepts calls and routes them accordingly. If you have called a POTS number, your MTSO routes that call to the conventional phone network and routes the return voice signal back to your cell phone through the tower handling your call, where it is sent to you as a radio signal. If you have called another mobile phone, then the MTSO routes the call to the transceiver handling that phone, and then back to you.

While you are connected to the mobile network, the MTSO tracks your signal strength. The MTSO assigns your phone to whichever transceiver receives the strongest signal from your handset. As you move away from one transceiver your signal grows weaker, while at the same time, as you get closer to a new transceiver it receives a stronger signal from you. The MTSO then assigns the next transceiver to handle your call, where you must authenticate again, and switch to the new transceiver's frequency. This hand-off between cells occurs without you even noticing it and with no interruption in your call.

Note:The following case illustrates the vulnerability of 1G networks. In Florida, on December 21, 1996, a couple using a police scanner was able to eavesdrop on and tape a call broadcast on a 1G network. This call was between then House Speaker Newt Gingrich (R), Representative Bill Paxon (R-N.Y), House Majority Leader Dick Armey (R-Texas), Gingrich's Chief of Staff Dan Meyer, Ed Gillespie
(Communications Director for the Republican National Committee), and attorney Ed Bethune. They were orchestrating a GOP counterattack to the charges that Speaker Gingrich was facing from the House Ethics Committee. This phone conversation was in violation of an agreement that Speaker Gingrich had with the Ethics Committee. The couple supplied the tape to an unidentified Democratic member of Congress, who likewise supplied it to the New York Times. Because of the interception of this call, Speaker Gingrich suffered a lot of political damage, and the press had a field day with the story.

1G technology is obsolete and been replaced by newer networks in most locations. There are some 1G networks still in operation in remote parts of the country, and in some places overseas. While traveling, you may actually connect through these networks, even with newer digital phones; however, advanced features such as messaging and data are usually unavailable while roaming in analog mode.

Insider insight: All mobile phones have a unique set of identifiers that are used to authenticate them on a network and route calls. Cloning is illegally copying one cell phone's identifiers onto another phone, allowing the user of a cloned phone to make calls on a victim's account without paying. When 1G (analog) system was common, fraud from cloning was a real problem.

Analog phones broadcasted their identifiers in the clear with no encryption. Criminals could use modified scanners to capture cell phone data, and then copy it onto illegal, cloned phones. Criminals often collected thousands of numbers in a single day, and the revenue lost to fraud was substantial.

The use of digital PCS has reduced the incident of cloning, but it hasn't been eliminated. Digital phones don't broadcast in the dear; they use digital encoding or encryption to secure all voice and data transmitted. However, when PCS phones roam between networks, or are using an analog cell tower (in analog roam) it's possible to capture the identifiers and use them to done a phone.

Criminals can done some phones with just the area code, phone number and the system ID. The system ID is unique to a specific carrier, in a particular geographic area. It is unlikely that you will ever be a victim of this form of fraud, but knowing about it will increase your awareness and allow you to stay alert to the possibility.

1G networks presented a range of technologies, including the following systems and services:

- Advanced mobile phone service Advanced mobile phone service (AMPS) is a 1G technology originally tested in the late 1970s, and later became a commercial service in the early 1980s. AMPS used a technology called frequency division multiple access (FDMA) that divided the 800 MHz radio band used by AMPS into 30 kHz channels. Each call on an AMPS network required a dedicated channel. Increasing capacity on an AMPS network required adding channels. AMPS was the primary mobile phone service in North America prior to the arrival of second-generation (2G) networks.

- Cellular digital packet data Cellular digital packet data (CDPD) is a technology developed as an add-on to 1G cellular networks. CDPD allows a 1G analog network to handle digital packet data, although at only 19 Kbps. CDPD modems are available for notebook computers and PDAs. CDPD service is available from several different wireless carriers in the U.S.

- Total access communication system Total access communication system (TACS) is an analog 1G network that was developed in Europe in the late 1970s. TACS is modeled after AMPS, and like the U.S. network used FDMA. In the U.K., a version of TACS called ETACS (extended TACS) was widely used.

Promotions:

Everywhere you look you are going to see great deals and special offers. Like anything else you buy, you're probably going to see the best deal right after you sign with a different company. Often these deals include a "free" or reduced-cost phone in exchange for signing a lengthy contract. Usually by the end of the contract you've paid for the phone twice with hidden fees and higher per-minute rates.

Your plan may offer special features free-of-charge for a specified period, but what will these features cost when that period expires? Will you be able to cancel them without penalty?

By -the-Second Billing

Most cellular plans are billed by-the-minute. That is, if you make a call that lasts for one minute and one second, you'll be charged for a two-minute call. Would you pay for three gallons of gas if you pumped two gallons and one ounce? No you wouldn't, and you shouldn't have to pay for cell time that way either.

There are by-the-second billing plans available, where you'll only be charged for the actual amount of time that you spend on the phone. The by-the-second rate usually begins after the first minute; anything less than 60 seconds and you'll still pay for at least one minute.

You can save a lot of money this way if you make a lot of short local calls every month. If most of your calls are long conversations, or long distance, you won't see much of a saving.

Pre-Paid Wireless

Pre-paid wireless service has some advantages. You never have to worry about overtime charges because you buy minutes in advance, and you aren't locked in to a one- or two-year contract. However, you'll usually pay more per-minute than you would if you signed a contract, and you'll have to buy your own phone.

If you have bad credit or no credit, then pre-paid is likely the way you'll have to go. Some carriers may give you service with bad credit, but you'll have to pay a hefty deposit fee.

Not all phones enable you to input Web address; some only enable you to select from a list that you have set up via your carrier's Web site.

You also may be able to set your bookmarks and preferences for Web sites via a Web page using your PC. This way you can sit down and input all of your Web addresses, contacts, and e-mail addresses without adding to your airtime. Your provider may have the most popular wireless portals and sites bookmarked already. Check the list and add any sites that you frequent to save time when you're browsing with your phone.

Once you've signed into some sites you can remain logged in, even between wireless Web sessions. This can keep you from having to enter a long user-name/password combination when you visit the site again. (Be careful about doing this; you don't want to lose your phone if you've remained logged into an e-mail account like Yahoo e-mail, or MSN Hotmail or a shopping site like Amazon.com. Whoever finds your handset would then have access to those accounts and all of the information contained in them.)

Some researchers are attempting to reduce this misclassification of data by cross-referencing phone bills and accident reports. By looking at the call times on phone bills and comparing them to accident reports, it is possible to establish a causal relationship between cell phones and auto accidents. Still, this method isn't perfect either, because it assumes that time data is accurate on both the bill and the accident report.

A 2001 survey conducted by the National Highway Transportation Safety Administration (NHTSA) indicates that at any given time, three percent of drivers are using cell phones (not hands-free types), which means roughly 500,000 people are driving and talking at any time during the week. While the NHTSA maintains that there appears to be an increased risk of being in an auto accident while talking on a cell phone, the magnitude of the problem cannot be estimated due to a lack of data. Many states are considering laws against cell phone use (handsets, not hands-free) by drivers, and New York has already passed legislation to that effect.

The NHTSA is still sorting the data out. In the meantime, we can all use a little common sense. Don't talk on your cell phone while driving unless you have a hands-free headset, and never send e-mail, check e-mail, or surf the Internet while driving (two percent of all drivers admit to doing this).

Insider insight: Using a hands-free headset while driving is a smart move. Even better is using a wireless headset .Several headsets are available that use Bluetooth networking technology to connect to your mobile phone. Using one of these headsets, you can place and answer calls without even taking your phone out of your purse or briefcase.

The headsets work best with phones that support voice dial and voice command. Bluetooth headsets will connect up to 30 feet away from your phone, and operate with both Bluetooth-enabled and non-Bluetooth phones (with an adapter). For added security, choose a headset that supports encryption.

Caution: Messing with your phone and trying to unlock hidden features could render it useless and violate terms of your contract with your cell carrier. It really isn't worth the trouble; especially since any cool customization that you'll want to do (graphics, ring tones) can be done without unlocking anything.

There are one or two handsets that have hidden games, usually hidden within other games installed on the phone. An Internet search will reveal if your model of phone has any hidden games and how to unlock them. These are generally limited to some Ericsson and Nokia handsets.

Gaming on your mobile device:

There are several Web sites that offer game software for your mobile phone. Although gaming capabilities vary from phone to phone, newer models, like the Nokia N-Gage, feature games that rival some Game Boy titles. The trend of gaming on cell phones (dubbed casual gaming) is growing quickly as more game developers and better games appear all the time.

Unlike desktop and console games that can be extremely complicated and have a long learning curve, most mobile games are almost intuitive. They may take only a moment to learn and a few minutes to play. The limitations of mobile devices have led developers to be creative and create simple games that are entertaining and addictive.

In most cases, you will only be charged airtime when downloading a game, not when you are playing it. The exception to this is if you are playing a multiplayer game over your carrier's network, or a game that requires you to interact with a game server, like a WAP game.

If you're an avid gamer, remember that gaming can be a drain on your phone's battery. Games utilize the phone's processor and display more than placing a call does; and they are more than a little addictive, so you can quickly find yourself spending hours playing them.

The problem with anecdotal evidence is that it fails to establish a causal relationship between cell phones and cancer; it merely states that Group A uses cell phones, and has a slightly higher incidence of cancer than Group B, which doesn't use cell phones. For all we know, Group A also smokes three packs of cigarettes a day and works at a chemical plant.

The big misunderstanding here involves the difference between ionizing and non-ionizing radiation. Mobile phones produce low-energy, non-ionizing radiation. Ionizing radiation is radiation that is very high frequency (above a million MHz for X-rays) and high energy, which enables it to break chemical bonds such as those found in human cells. Ionizing radiation can damage DNA molecules, causing cell death or even cancer.

Cell phones are low power and operate at a much lower frequency than sources of ionizing radiation, such as X-rays. The non-ionizing radiation produced by mobile handsets cannot break chemical bonds. At very high levels of exposure, higher energy non-ionizing radiation can cause warming of tissues, much like a microwave, but handsets do not have that much power.

If you are concerned about possible health risks, limit your exposure, use a hands-free earpiece, and continue to monitor the research.

Insider insight: With the worries about cell phone-related health risks, it was inevitable that a few products would appear that would claim to mitigate some or all of them. The supposed health risk that creates the most concern, and headlines, is a proposed link between cell phones and brain cancer. One product that claims to mitigate this threat is a cell phone radiation shield.

These shields usually consist of an oval sticker that fits over the earpiece of your phone. Manufacturers claim that these bits of plastic, sometimes metal mesh, block harmful radiation. Even if the non-ionizing radiation from a cell phone were dangerous, placing a sticker over the speaker on your phone wouldn't protect you. Sound waves emanate from the speaker, not radiation. In general, radiation emanates from the phone in all directions so these stickers do nothing to block RF radiation.

Some manufacturers sell cell phone cases made of material that they claim blocks RF radiation. I remain skeptical that they can even block the RF waves, not to mention they usually have a dear plastic window over the keypad that will definitely allow radio waves to penetrate. If radiation shield cases really did work, you wouldn't be able to use your phone, because it wouldn't be able to send or receive a signal. So obviously, plenty of RF is escaping, not to mention what comes out of the antenna (which isn't shielded).

If you are genuinely worried about using your cell phone, don't waste your money on these products. Buy a headset and keep your phone away from your head. It's safer while driving, too.

Activation Fees:

A common "gotcha" is activation fees, charges you incur by signing up for a service and having them turn on your phone. Sounds ridiculous doesn't it? That's because it's the equivalent of charging someone to flip a switch. I can't think of too many other businesses that penalize customers for bringing them business.

Most carriers waive activation fees if you sign a contract. What many people don't know is that they will also waive the activation fees if you insist upon it. They want a new customer, and because you have so many other service providers to choose from, most waive the fee because they know the competition will.

Roaming

This is a quick way to run up a big cell bill if you aren't careful. You can get plans that offer no-roaming charges, but be careful; this usually refers to roaming within your carrier's own network and doesn't cover roaming on another provider's network or analog cell sites.

Choose a carrier that doesn't charge for roaming within their own network; most of the big cell companies don't. You should also double check the roaming feature of your cell phone because you may have choices that you can set to prevent inadvertent roaming charges. Often you can choose among the following:

- Only use the (insert provider name here) network

- Analog roaming where available

- Automatic setting

The problem with an automatic setting is that your phone may connect to an analog tower and go into roaming mode even when your provider's network is available. This can happen if the signal from an analog tower is slightly stronger than one from your own carrier's network. Choosing analog roaming may cause the same problem if you wander into an area where there is a strong analog signal. The safest setting is to leave your phone locked to your carrier's network.

Note:To provide greater connectivity, many phones come with default settings that allow automatic choice of roaming. Double-check your setting.

Overtime Charges:

Boo, hiss, everyone hates being charged an arm and a leg for going over your allotted time. Sometimes the per-minute charge is more than double the cost of the per-minute charge on your land phone, so read your contract carefully and get a plan that gives you enough minutes to prevent overcharges without wasting money on minutes that you don't use.

This can take some fine-tuning, but some cell companies allow you to increase or decrease the minutes on your plan as you go. Just be aware that doing so may extend your contract. You also can consider pre-paid service to avoid overtime charges.
Some companies have started to allow consumers to rollover their unused minutes from one month to the next. You can't keep them indefinitely, and there's a limit to how many you can rollover each month, so review your plan. Still, this is a great way to save money and avoid overtime charges.

Early Termination Fees:

Every contract has these clauses. I repeat every contract. This is how cellular companies subsidize all those free phones that they give away. If you don't fulfill the contract you can pay anywhere from $150 to $500 in penalties. There are usually no exceptions to the early termination penalties, even if you terminate because of poor service. This is why the mobile phone industry is such a buyer-beware marketplace.

Most contracts make no exception for poor service, the company's inability to live up to its part of the contract, or even death of the cell phone user. That's right: If you die, your family may have to pay over a hundred dollars to cancel your cell phone service.

Read your contract carefully, and insist on having the details of the plan explained to you. You are responsible for any agreements you sign, no matter how unfair or unethical they are. If you need to cancel a cell contract because the service if poor, discuss it with your cell provider, and if they won't do the right thing, call the Better Business Bureau (BBB), your local newspaper or news program's consumer advocate, or if your state has one, the consumer affairs department.

Your choice of smart phone depends on the cell carrier that you choose. Just like standard phones, carriers support specific models so you'll have to choose from what they offer. Smart phones are all digital; I haven't found a model that also supports connecting via an analog cell site. This shouldn't be a problem if you're in a major U.S. city, but if you travel throughout the U.S. you need to be aware that you'll be unable to use the phone outside of your carrier's digital network.

Other than Palm OS and Windows Mobile smart phones you also can consider Blackberry wireless handhelds. Known for its two-way messaging and e-mail devices, Blackberry also produces wireless handhelds that include voice, SMS messaging, and e-mail. These devices aren't full-fledged PDAs; they're more wireless organizers and don't have anywhere near the functionality of a Palm or Windows Mobile smart phone.