Someone PLEASE help me and clear this up. I've been to three Walmarts and called ST myself and still don't understand because everyone explains it SO bad. I have two iPhone 4s's from just upgrading phones within the family etc, anyway, they both are just sitting on my table unactivated and all. Now, my aunt and uncle want to have iPhones on the most affordable plans,I prefer ST since it uses AT&T towers, and I was going to give them both each an iPhone. Now, do I purchase the micro AT&T sim card for ST, go into walmart and let them activate it and buy the $45 card and they take care of everything? What's this I read about unlocking and everything? Can't they just stick the GSM sim card in and it will work? Please someone clear this up. Also, what's the better deal out of the three? I don't know the difference between net10 and ST. I see this Walmart Family Mobile is using Tmobiles towers and it's $40 a month unlimited but i'm not too much of a T mobile fan. What do NET10 and ST use? Thanks!