Will your phone work outside the country? And if it does, will calls be outrageously expensive?
The answers are complicated, but a crash course in cell phone engineering and jargon can really pay off. Instead of paying $2 or more per minute, you could end up getting free incoming calls and paying pennies per minute for outgoing calls.
You can always rent or buy an inexpensive phone that will work in whichever corner of the world you plan to visit. But the biggest savings will come if your phone will work abroad. Many AT&T (formerly known as Cingular) and T-Mobile phones will work outside the United States if owners remove the little SIM card, or subscriber information module, and replace it with one from a foreign carrier.
First, you need to figure out the type of technology used in your destination country. Chances are it is something called GSM. In the United States, there are two main standards, GSM and CDMA. Europe and much of the rest of the world use GSM.
For maps and detailed information about the world's cell phone carriers, see http://tinyurl.com/yrt9p, http://tinyurl.com/237bbg and http://tinyurl.com/22x7cr.
The next step is to figure out the technology used by your carrier and the version used in your individual phone model. AT&T and T-Mobile use GSM. Sprint and Verizon use CDMA, but each company sells a couple of combination CDMA-GSM phones that will work outside the United States.
The majority of Sprint and Verizon customers traveling to non-CDMA countries will need to rent or buy GSM phones, either from those providers or online.
Sprint rents a Motorola Razr for $55 for the first week and $70 for two weeks. Verizon charges $3.99 a day for a Motorola SLVR. Both carriers charge $1.29 and up per minute of airtime.
EBay and other national Web sites sell new and used GSM phones for $20 and up. You'll need to make sure the phone will work in your destination country as explained below.
Not all GSM phones from the United States will work on foreign GSM networks. Say, for example, you plan to travel to Bosnia and your phone is a Motorola Razr from T-Mobile. The phone is GSM, which means that you might be able to pop out the SIM card and replace it with one from a Bosnian carrier.
To find out, look up your phone online, either on the manufacturer's site or via Google.
We'll search using Google for "Motorola Razr T-Mobile specs." It turns out that the Razr is a quad-band phone, which means it is capable of using any of the four most popular GSM frequencies - 850, 900, 1800 and 1900.
Just to be sure, we check the GSM World site listed above and find out that the three main carriers in Bosnia use GSM 900. So far, so good.
But what if your phone is an Audiovox 5600? It's an AT&T phone. We search for "Audiovox 5600 specs" and find that it is a tri-band phone that works on the 850, 1800 and 1900 bands. Unfortunately, it won't work on Bosnia's 900 band.
The Audiovox 5600 and other tri-band phones would work on many foreign networks that use both the 1800 and 900 bands, but not on networks in China, Bosnia and a few other pockets of the globe.
The next step in our example is to have the Razr unlocked. Phone carriers add a software lock to prevent subscribers from using the phones on competing networks. T-Mobile will unlock a phone 90 days or more into the contract period. AT&T will unlock a phone after the contract period has expired.
But there's no reason a phone owner has to wait for the carrier. There are plenty of services, local and online, that will remove software locks for fees ranging from $10 to $60. It's legal because you own the phone.
At San Diego-based UnlockCellphone.com, owner Lincoln Han said that about half of his customers are GSM phone owners headed overseas for vacation.
"People realize they can take an unlocked phone abroad and save money," Han said. "You can get free incoming calls in most countries and pay local rates instead of expensive roaming minutes."
Once a phone is unlocked, you're free to use a SIM card from a foreign carrier. Travelers can buy the cards in advance or pick them up at the destination airport or at locations throughout most major foreign cities.
Online companies such as Telestial.com and CellularAbroad.com offer SIM cards with prepaid minutes. Telestial also sells GSM phones, while CellularAbroad rents and sells phones.
It pays to scrutinize SIM-card offers, which vary considerably. A Chinese SIM card from Telestial.com costs $69 and includes $18 of prepaid airtime at 7 to 16 cents per minute for local calls.
A card from PandaSIM.com costs $29 and includes $16 of prepaid airtime, with rates from 10 to 24 cents a minute for local calls.
Before you get back to over-packing your suitcase, another troubling thought arises: How will I charge my phone? Will I need an adapter for those funky foreign wall plugs?
Probably. See http://traveloasis.com/adapters.html for an illustrated guide to outlets worldwide.