Originally Posted by
MatthewAMEL
Oh, and be sure to turn Data Roaming 'off' when traveling anywhere outside the US (including Canada and Mexico). Your iPhone gets tons of data even when you aren't using the internet. (Visual Voicemail, for example, is a data service)
Be careful if you're ever on a cruise ship. I know someone who was on one and missed a few incoming calls (they have a tower/base station on the boat). Even though he didn't answer them, he got charged just for having the local tower ring down his phone some crazy amount.