I've got a question... I'm thinking of activating an iPhone with AT&T normally, then immediately cancelling service normally in a day or two. The iPod/PDA/YouTube/Wifi should still work. Now, what if I sell the unit along with the SIM? When the new user attempts to sync with a new computer, is the device AND SIM erased, as an iPod on a differnet computer would be? Or is my name and iTunes account, and credit card info now vulnerable to the new user? (I don't care about the phone number). Of course the other option is to sell the unit without the SIM.