As part of my getting an iPhone 3G, I'm giving my daughter my old iPhone. I have gotten a new SIM from AT&T and will be setting her up on iTunes this afternoon. I have a question though - she will be wanting to have her old Sprint phone number moved to the iPhone. Does she have to do this when she initially signs up with AT&T thru iTunes or can she wait and do it later on? The thing is she would like to use the iPhone for a week or so before transporting her Sprint number, just to make sure she has good AT&T coverage at her apartment and at the school she teaches at. If she has poor coverage, she wants to be able to cancel the AT&T account and stay with Sprint. Thanks for any replies.