Agree with pdxer, however, I've been using AT&T's international voice & data roaming plan when I travel overseas. The day I leave the U.S., I call and add roaming and the day I arrive back in the U.S., I call and cancel. That way, I pay a pro-rated fee and not for the whole month. I use it for the data primarily, but have voice just in case I need it. I do not keep my iPhone turned on 24/7, only when I want to check for messages or use the web.