Searching for a way to use my Sprint iPhone 4S on AT&T and I stumbled across this. http://m.youtube.com/watch?v=JSYkRPxFgNg&desktop_uri=/watch?v=JSYkRPxFgNg After watching the video I immediately contacted the company, Space Coast iRepair and asked how they do this and how much it would cost. This is the reply: Hi, thank you for contacting us. We unlock the CDMA 4S iPhone for $69.99 and it can be used with any GSM carrier worldwide. You would have to send phone in for programming. You can contact us at number listed below or toll free at 1-855-622-4583. This post may seem like minutia to most people but it would be EXTREMELY helpful for somebody who wants to change their Sprint/Verizon iPhone 4S to AT&T/T-mobile. There is in fact a factory unlock solution and NO I am not a rep from this company.