It is widely known that Apple adds a data plan to iPhone users accounts without one (contracted accounts, not go-phone accounts). They can do this because they see the IMEI number of the phone in their system, know it's an iPhone, and add the plan accordingly. It seems to me that if you put your iPhone microSIM card into an iPad, AT&T will see the IMEI number for the new device, and charge you accordingly. That is, $15 for anything under 250MB, and $30 for anything over that. Alternatively, they could figure that if you're using it in the iPad, you're not using it in your iPhone, so it's no big deal. This approach would more than likely lead to people with both devices copying their SIMs and using one in each device at the same time, and as so, I don't see AT&T taking this approach. Thoughts?