Those of you who have sold your iPhone but kept the data plan on your account, when you go by a iPhone 3G, what if they ask to see your old iPhone. Because I am planning to borrow my friends iPhone which they don't use since its broken, but she still has the data plan on her account and is temporarily using a crappy phone till the 3G. I was going to borrow it, activate it on my sim, and just put my sim back in my phone till Friday. Lets hope all goes well.