quick question guys im thinking of getting the iphone 3gs on pay as u go and then getting an o2 simplicity 12 month contract - more mins, more texts and fewer months im tied down to. first of all will the iphone work on it wihtout needing to unlock etc? how do i activate it as from my first iphone i had to unlock it straight off then again my sim at the time was a voda one? what featres wont work other than visual voicemail? thanks in advance!