I would offer an alternative for anyone unlocking an AT&T phone. Call AT&T customer service, when they ask your number, tell them you don't have one (you are calling from something other than your cell phone, naturally). Tell them you purchased a phone on EBay, and need to get it unlocked.
I've never had a problem getting the unlock code, and have received it in as little as five minutes on the phone. I've unlocked phones I've had less than thirty days doing this.
I unlocked my 3 phones from globalunlockcodes. com
2 lg vu and one blackberry 8320
just $1.99 each
and they guys are fastest - i guess they have automated machine or somthing. i got my unlock code within an hour.