I am currently on U.S. Cellular. I am switching to Straight Talk. I am going to risk it because, I hate my current service. I want to put an iPhone 4 (Originally AT&T) on to Straight Talk. I know this is possible, I have done a fair amount of research on the subject. I need to know how to change the APN settings because the iPhone 4 from AT&T prohibits you from changing the APN Settings. You have to do this to utilize the Data and MMS services of Straight talk. Aren't ATT and T Mobile both GSM Carriers? I have read some information on having to cut the sim card??? Please help!!!! What I mean by "cutting the Sim Card" Is that On a few forums I have read that in order to get the service to work as advertised, You have to cut the sim card because it is a Mini sim in the iPhone 4. I think the ST Package at Walmart has a mini and a regular sim though. I just need to clarify some things before I get myself into a challenge I can't solve!! Thanks for Your time.. and thanks for your answers in advance! 