I just don't get why Apple doesn't just sell a higher-priced, unlocked iPhone, so that you don't have to get yourself screwed by your local carrier.
AT&T is weathering the downturn relatively nicely thanks to their exclusive deal with Apple. The ~$200 check they cut Apple per 2-year contract is paying for that exclusivity plus like-advertising.
That was for the 3G though. I don't know if they still do it for the 3GS.
iPhone 3G: $499 (8GB) and $549 (16GB)
iPhone 3GS: $599 (16GB) and $699 (32GB)