I have one of the original iPhones -- on an AT&T plan. I will be traveling from the US to France next month -- and am wondering -- will the phone work there? I know I need to expand my plan (probably??) -- but once I get the coverage -- will the technology work???
you will need to either sign up for an international plan with at&t (expensive) or jailbreak and unlock and buy a local pay as you go sim there (not as expensive).
The advantage of the international plan / roaming plan is still having the same phone number ... whether that's worth the over-priced expense is up to you. Another option, if you don't want to jailbreak your iPhone, is to buy a new iPhone in France with a pay-as-you-go / pre-pay plan and then sell it before you leave or when you get back (assuming France has a pay-as-you-go plan for the iPhone).