So, you want to upgrade your current phone to the iPhone 5? The first step you need to take, is to see whether or not you qualify for a fully subsidized upgrade with no penalty.
AT&T makes this process particularly easy, all you have to do is dial *NEW# (*639#), and you will receive a text message laying out your eligibility. For Verizon users, Big Red has provided a website that you can go to to verify your upgradability, or you can dial #874.
In the past, AT&T has let users who are only partially through an existing contract to upgrade without any penalties. Whether or not they plan on doing this with the iPhone 5 remains to be seen, but from what I've seen thus far, it's not looking entirely promising.