SquareUp. It's a card reader that's about 1"x1" that you plug into your mobile device. Using the free SquareUp app, you can now accept credit card payments for a low, low, 2.75% service fee per transaction. The best part? The car reader is FREE! I may never take a personal credit card payment ever, but just knowing that I can is pretty damn cool. If you owe me money, watch out! I now take Visa, MasterCard, and Amex.
At first I was completely blown away by SquareUp. I ordered one immediately, of course. I've since reconsidered. Once NFC becomes mainstream, SquareUp better be well poised to be the PayPal of mobile personal payments or they'll easily be passed over by integrated hardware services. Maybe not. Either way, pay up suckers!