Tips for Using Cell Phones Overseas

Buy a SIM chip

If you have a GSM (tri- or quad-band) phone, ask your service provider to unlock it. You can then swap out the SIM card—the plastic chip that gives a GSM mobile phone its number—for a foreign SIM card. Buy one from companies like Cellular Abroad (cellularabroad.com), or at a newsstand when you arrive. Rates start at about $20, plus pre-paid minutes (generally around 20 cents per minute to the U.S.). If you're country-hopping and don't expect to make lots of calls, pick up a global SIM card; cards and rates are more expensive—around 50 cents per minute—but you'll keep the same number and won't have to buy a separate card for different countries. Incoming calls are generally free.

The Upside: Easy to find; since minutes are pre-paid, you won't get hit with mystery charges.

The Downside: You need a tri- or quad-band GSM phone, and most SIM-card sellers can't unlock the phone for you, or will charge you an "unlocking fee."