Use your mobile device to accept credit card payments. To swipe cards, you'll need Square's quarter-sized plastic dongle (they send you one for free). The money is deposited into your bank account the next day (less a 2.75 percent transaction fee), and your customer gets an emailed receipt instantly.
WIRED Accepts Visa, MasterCard, American Express, and Discover. Doesn't save credit card numbers.
TIRED Buyers may not believe it's the real deal.