Best Buy today has an one-day special promo. Those who buy the phone in-store on August 22 only can get it for free when paired up with a two-year AT&T contract. Its deal makes it the cheapest deal for an iPhone 3GS.
Apple is widely presumed to be phasing out the iPhone 3GS entirely when it introduces the iPhone 5. Some signs have already emerged that the iPhone 4 will be the new entry model. Canadian provider Koodo started supporting Apple this spring by only carrying the iPhone 4, hinting that Apple wanted to cut down on iPhone 3GS production.
iPhones have rarely been free in the US, although the discounts have been common in recent years for Europe and other areas where carriers alter the price depending on the attached rate plan.