Hi, I have an iPhone 3GS currently on ATT. I'm going to go use my upgrade today to get the iPhone 4. However, I'm going to give my 3GS to my little brother once I get my iPhone 4. He is also on ATT (we're all on the same family plan). He is planning to go abroad this coming month, and was wondering if he would be able to purchase a SIM card from there and put it in the iPhone, but when he comes back continue to use that same iPhone on ATT (with the sim he has now; basically he will take his ATT sim out when he leaves and put it back into the 3GS when he returns). I told him, I would jailbreak/unlock it for him. I'm planning to follow this guide I found on iClarified: http://www.iclarified.com/entry/index.php?enid=12349&laid= HOWEVER, if you look at "Step Six", it says: "NOTE*: Deselect Activate if you have an iPhone legitimately activated on an official carrier." Technically it is legitimately activated on ATT, but I need it to work with a different SIM card when he goes abroad, but when he's back I need it to work again on ATT. What do you guys recommend? I was planning to follow the iClarified guide to jailbreak as stated (i.e. DESELECT activate and not unlock it), and then use the following ultrasn0w guide to unlock: http://www.iclarified.com/entry/index.php?enid=4253 Do you guys think this is the way to go? Any help will be much appreciated! As always, you guys are a wonderful help!