Switching from Straight Talk to AT&T
I currently have 3 phones with Straight Talk. I have one that is unlocked that I will be switching now to AT&T. My question is, I also have an Iphone 4 and a Samsung Galaxy S3 that I bought with Straight Talk/ as Straight Talk phones. Can I switch these over to AT&T with problem as well? If so, do I need to get SIM cards?