I bought my 3GS from a family friend after their AT&T contract expired. I had to jailbreak and unlock via the iPad firmware hack for use on T-Mobile. I'm currently on 5.0.1 with 6.15.00 bb. I'd like to eventually get my gps back. I honestly don't care AT ALL about having the jailbreak. I only have the JB so I can be unlocked and work on T-Mobile. If I get the person I bought the phone from to ask for the unlock from AT&T, can I just upgrade to iOS 6 and be functioning? Do I have to do the baseband downgrade from 6.15.00 first? If I can't get the person to ask for the unlock from AT&T, can I still downgrade the baseband and stay at 5.0.1 (I didn't get the blobs for 5.1.1)? Thanks for any help on this - I'm at that dangerous level of knowledge that allows me to get far enough to really mess things up.