With regular mini SIMs with ATT, if you "deactivate" the SIM, it can no longer be re-used. You will have to go to the ATT retail store to pick up a new mini SIM and get it re activated. It's free (or you can call them and they will send you a new mini sim for free also. What I'm concerned about is the $15 charge ATT charges to replace a MicroSIM card. So if I sign up for the $15/30 iPad data plan and cancel the data contract, can the same MicroSIM be re-used again if I choose to re-active it in a few months? Can only the original person/billing credit card number use the same MicroSIM. Or can I give the MicroSIM to my brother and he can use it on a different iPad? Or is the MicroSIM that shipped with the iPad "preactivated to just that specific iPad so it can be re-activated anytime" but can't be used on another iPad? I can't seem to find the answer to my MicroSim questions. I don't want to keep paying $15 for a new MicroSim each time.