I got a sealed iphone from my dad as a gift , he bought it from a freind who works for rogers and had his hardware upgraded due to his contract..and he sold it to us
sealed.. all i had to do was plug in the iphone to the usb, and insert my pay as you go sim..and done
no store required activation done, everything working.
just telling my expreince with a sealed iphone 3g.
dont know how the stores do it , i just opened the phone and plugged into itunes, and it did everything for me.