I've got a friend who is buying an iPhone 3G S, and is giving me his 3G. I have AT&T as my current cell provider, and I don't want to get an expensive new plan. If I unlock the iPhone, can I put my old cell's SIM card in it, can I use the iPhone as a phone? If so, what if I want to use Edge (3G is not available here. Supposedly, it will be coming in a few years though), how would I go about getting a data plan? Could I just sign up for unlimited Edge from AT&T for my old cell, and use that on the iPhone? I really don't want to ask an AT&T person, because I don't want to start any trouble with them.
