You can Jailbreak the OTB 1.1.2, but you can not unlock it. It will only work with ATT Network .The reason is not the actual firmware but the bootloader that is making it, thus far, impossible to "Unlock" Out of the box 1.1.2. Updating TO 1.1.2, however, you can still unlock it. but if you got a phone with 1.1.2 strait from Apple. Yer gonna have ta wait till they figure out this one.. Rumors say 2-3 weeks till someone figures it out, depending if 1.1.3 comes out anytime soon.
Thanks for the warnings guys... not what I'm looking for. Just looking for a little hacktivation guidance, from those that have trekked this road before. Until the phone is 'activated' you can't downgrade firmware, you can't JB.