Best Buy is giving away free 8GB iPhone 3GS smartphones to customers today. Supplies are limited, and you can only get the deal in-store with two-year new or upgrade activation. Sure, the iPhone 3GS is a year-and-a-half old, but this is the first time we've seen any iPhone given away free with contract. With the holidays and all, you can certainly bet that any teens in your household would love to unwrap this one on Christmas morning. Speaking of which, be sure to peep our 2010 Holiday Gift Guide!