I surf a lot of travel message boards and am always amazed by the number of people who are asking about how to travel around the world with their cell phone. Are you people nuts? It's going to cost you a bundle, you have to have different sim cards for different locations, and it's another gadget that allows you to tune out and act like you're still home. Leave home at home--there are better options.
For one thing, there's e-mail, which you can send from almost any little town these days. Many Internet cafes are even set up with webphones, Skype phones, and other things that let you talk for next to nothing. Then there are phone cards, which are small, light, portable, and cheap.
I've been trying out one from Pingo and it's a dream. Once you register the card online, you can just keep recharging it and it's pennies per minute. I just talked to someone in Canada for an hour and a half solid for about $2.50. They have local access numbers for other countries, so if you're in Mexico, for instance, you can spend under 10 cents a minute, instead of the 50 cents a minute you'd spend with an official telecom monopoly card. They route all the calls over a VoIP system--as in through the Internet backbone instead of through the normal legacy phone lines. Think of it as a Skype call that actually sounds normal.
Want a free one to try? Click on the banner here.