Need cell phone service while traveling internationally? Even for the infrequent traveler, getting international wireless service is easier and cheaper than ever before. To avoid overpaying for international cell phone service, find out how different global roaming services work.

The easiest option in the U.S. is available to T-Mobile and Cingular Wireless customers who currently use tri-band or quad-band cell phones (sometimes marketed as "world phones"). Because the technology standard used by T-Mobile and Cingular Wireless phones (and a few AT&T phones) is similar to the one used by the rest of the world, GSM cell phone users can more than likely just take their current phones abroad with them.

If you already have a GSM world phone, all that's required is making sure your wireless service plan allows for international roaming. If it doesn't, simply call your cell phone carrier and ask for this feature to be activated on your existing cell phone.

But the easiest option is not necessarily the most cost effective, so you'll want to consider how, and how often, you'll be using your cell phone internationally and see if you can find a more cost-effective cellular plan based on your calling needs.

Buying Separate SIM Cards
For the hardcore traveler or those who spend extended time abroad, the best advice is to buy a GSM phone (make sure it's multi-band and supports the frequencies used in the locales in which you're staying), ask your carrier to unlock the phone, and purchase pre-paid SIM cards from the places you'll be traveling.

Since most countries operate on a "calling party pays" system, incoming calls to your international SIM will probably be free. Your cost per minute for placing local calls will depend on the SIM card.

Of course, you can make every call a local call by buying a different SIM for each country, but since your mobile phone number is associated with the SIM card and not the cell phone handset, it may become very complicated for your family and coworkers to keep track of which number to call in order to reach you. It would also mean keeping track of your cellular usage on a country-by-country basis.

Renting an International Mobile Phone
If you travel infrequently and don't anticipate using a mobile phone much or at all -- but still want the security of having a way to be reached in case of emergency -- consider renting a cell phone specifically for your trip.

Rental cell phones are convenient and simple to use. However, these mobile phones tend to skimp on features, so they won't meet the needs of power cell phone users who rely on data messaging and other smartphone features.

If you anticipate using a wireless phone rental service more than once, or need to use advanced features while you're traveling, you may be better off buying a cell phone for every day use that is also capable of global roaming.

Taking Your Own GSM Cell Phone
If you don't travel internationally that often, being able to use your regular cell phone when abroad might be enough of a convenience that it's worth paying your wireless service carrier higher per-minute rates for global roaming calls.

Be sure to verify before you leave the country to make sure your cell phone will work abroad. Remember, not only must you have a cell phone that works on the GSM standard (Verizon Wireless, Nextel, Sprint PCS and most other U.S. service providers use the CDMA cellular standard, which does not work in the rest of the world) but it must also operate on the correct cell phone frequencies. Furthermore your carrier may need to know beforehand that you intend to use your wireless phone abroad.

No matter which you choose, keep in mind that using cell phone service overseas is going to be more costly than what you pay for local or national calls. Expect that global roaming will become cheaper over time, just as national roaming has become less of a hassle for U.S. cell phone users over the past few years. Until then, however, consider using your mobile phone less and just enjoying your trip!

Additional Information on Cell Phones