So you want a new iPhone, huh? Are you eligible for a new phone through your carrier? If not, you'll be stuck forking over $600-$700 and you don't want that. Not sure if you are? Don't fret, just follow these simple steps.
1) Click this link.
2) Choose Your Carrier.
3) Enter your phone number and the last 4 digits of your Social Security Number. Click OK.
4) You're done. Hopefully you're eligible.
Oh, and if you're wondering if it's better to buy your phone through Apple or carrier, it doesn't really make a difference in the long run. Though you might be able to talk a desperate salesperson into a discount at one of the carrier shops. [Apple]