I want a friend to upgrade their att phone to the 3gs, because I am not eligible for the low upgrade price. I currently have the 2g iphone, ATT phone with the $20 package If they get the phone: 1. Can they cancel the DATA package and give the phone to me. With no ramification except for the 2 year contract. 2. Can I just switch out sim card and keep my 2g data plan or will ATT know that I switched phones. And if they catch me do they back charge me for usage. Thanks for the help.