Hello! I've searched a few threads and online, but I haven't been able to find a very specific answer to my questions. I wanted to take my AT&T on-contract iPhone 4s to the UK and purchase a micro-sim card (maybe Vodafone/O2). In the past I've paid for the AT&T international data & calling plan which is quite a bit more expensive than a pay as you go sim card plan from a UK carrier. I'm not quite sure what my options are, and I have a few questions depending on what option I take. 1) Gevey ultra S sim card to unlock iPhone 4s From what I understand, the only way you can unlock a 4s with baseband 2.0.12 (other than purchasing an unlocked version) is to use the gevey ultra s sim. I'm thinking of biting the bullet and purchasing one. My questions are: a) Provided I can purchase a micro-sim card from a UK carrier (I have family in UK, so there is no issue with credit-checking, as they can buy me a micro-sim) after I insert the sim card + gevey module into my iphone, what settings do I need to change. I read online about changing some APN settings, how can I find this out? The problem is, it's impossible for me to test this out until I go to the UK, and by then, it might be too late, as internet access will be spotty. b) Can I keep the sim card/gevey sim module for a couple of years, and just top off the micro sim whenever I want to travel to the UK (I/family usually go every year)? c) When I am back in the US, can I remove the gevey sim module/uk microsim and insert my original sim card without any problems? I might have to change back the APN settings, but that's ok. My question is, will AT&T find out and complain? Do I even need to remove the gevey sim? Can I just keep it in my iPhone forever? d) Does my iphone 4s need to be jailbroken to use the gevey ultra S sim module? Believe it or not, I wasn't able to find a clear answer to this question. e) Can the gevey sim (Ultra S) work with iPhone4? The idea is that I can use it in any phone (and maybe future phones?). That way a family member can use it in their iPhone, regardless of if it is a 3G/3GS/4/4s? I think the answer to this question is a resounding NO. 2) Is there any other way to unlock the iPhone 4s? I have a previous iPhone 3G that I could ask AT&T to unlock for free, but that thing is pretty slow/out of date, and painful to use. Thanks for any help/feedback to these questions. I know I'm asking for a lot!