Hey. I have a lot of experience jailbreaking my iPhones and iPads but never unlocking an iPhone. I contacted AT&T this evening and they unlocked an old iPhone 3G that I have. Smooth process and was over with and unlocked with them in about 20 minutes and another 10 minutes to do the restore via iTunes and get the unlocked message there. I plan on giving this to my nephew so he can do prepaid on it. He's only 13 and my sister isn't ready for him to be on her contract just yet (plus she's on verizon and this will not work on that network), so we thought this would be a good start. My questions are: 1. Now that it is unlocked does he just need to get a sim card from T-Mobile or AT&T (or another carrier that uses GSM) and put it in the iPhone? 2. He should be able to get a prepaid sim as well and put it in right? 3. I'd rather not give him the phone with our old sim in it, does he need that for any reason? 4. Since the iPhone is unlocked, can it be switched between carriers now? (ex: one minute use a T-Mobile prepaid sim and the next an AT&T prepaid sim by just swapping them out)? Thanks for any info on this!