iPhone Tab

Existing AT&T customers can keep their rate plan and add a $20 a month iPhone data plan. Activation of the iPhone plan is done so on their phone via iTunes. There are also special plans for new iPhone customers as well as family plans.
-from MyiTablet

What about the 2yr contract, you may be thinking to your self well you have to either get a new 2yr contract or extend your current one another 2 yrs.

So take a look at the plans and see what fits you best, also check out the new Apple activation through itunes video HERE

Head over to APPLE for more info