I currently have an iPhone 3G and my wife has a 1G iPhone. AT&T just suspended my account for the period of time that I'll be in Afghanistan and switched us from a family plan to a single plan for my wife. I'd like to give my wife my iPhone 3G and then sell her iPhone 1G. Is it as easy as taking her SIM card out of her phone and putting it in my 3G or will that not work? AT&T lady said so, but she seemed unsure. Thanks.