I recently unlocked my iPhone 3gs to give as a gift to a friend who is on T-Mobile. However, he bought a new iPhone and signed up with ATT before I got a chance to give him the gift. Now I'm using the unlocked iPhone 3gs on my ATT account. What I'd like to know is how can I uninstall Blacksn0w, ie, how can I lock my iPhone 3gs and put it back to what it was prior to the unlock. Will doing a simple restore reset the phone back to factory default and lock it up again?