Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
best option is to check if it be unlocked via the carrier or grey market IEMI unlocks if it's AT&T by chance they are real cheap under $5 now. no unlockable basebands in two years. that should give you a idea.
 
Have been using a 3 unlocked/JB after running iPhone Configuration Utility.app in order to use ATT GoPhone sim (activated in another phone).

Would be hesitant to have ATT unlock (have heard they will for commitment free phones) since they only condone prepaid smart phone sims.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.