My iPhone 3GS broke 2 months ago and instead of getting the iPhone 4, I decided to wait awhile to see if there was a new iPhone coming out anytime soon. I had an unlimited data plan that I wanted to keep so I called AT&T and they said I could use any AT&T smart phone and keep my plan so a friend let me have their old Motorola Backflip to use in the mean time. When the 4S was announced, I preordered the second preorders opened up at 12am and ordered a white 4S 64gb through AT&T. I was given the option to keep my unlimited data plan, which I chose and the phone is currently en route to be delivered tomorrow. My questions are... I want to start the iPhone 4S off as a BRAND NEW PHONE. I don't want to use any of my backups from my old 3GS. I want it to be brand new. But in order to keep my unlimited data plan, do I need to insert the sim card into the 4S that was in my 3GS that I moved to the backflip or can I just not even worry about that and still keep my unlimited data plan? I would assume that the unlimited data plan has nothing to do with a sim card and is more about what is on your AT&T account, but I wanted to be sure.