G1 unlocked to att help

hi im thinking of buy a G1 from a person who has it and has the data plan. if i unlock and put in my sim card and turn it on will it ask me to sign up with Gmail or will it skip that becase the person that had the phone before me already did that. need some help becasue this is what is going to make my decison if i buy this phone.

If you or the person you buy the phone from does a Factory reset of the phone, yes you will be required to sign into G-Mail when you turn on the phone. I would recommend doing so from a computer prior to doing it on the phone, when I had mind it took about 2 hours to finally get signed up and logged in.