Buying a used iPhone 3G, what do I need to do?

[doowstados]

Hey guys, I'm new to the whole iPhone scene. I've modded several phones including RAZR's, Blackberry's and a couple of HTC phones but finally decided to hop on the band wagon and buy an iphone.

My question is, what do I need to do in order to activate this thing? I am currently using an HTC Fuze on my AT&T contract. Since it is already on a smartphone contract, should I be able to just pop in my sim card and have it work? If not, what will I need to do? Will I have to renew my contract? If so, are there ways around this? Thanks for the help.

[jkmonkey]

Since your on AT&T all you need to do is put your sim into the iPhone. If there's pic of iTunes and a USB cord on the screen just connect it to a computer that has iTunes installed.