Hi everyone, Hope you all can help me. I recently bought an 8gb iPhone and just now realized that 8gb is definitely not enough space for what I need. So I decided to upgrade to a 16gb. I'm about to sell my 8gb and buy a 16gb. While I'm in the process, I plan to use my current iphone sim card on another phone (razr). After that, I plan to put the same sim card into the 16gb. Would there be any problems with this process? Do I need to contact AT&T in order to do this?