Check out the recent CNNMoney.com article on mobile credit card processing:
No more fumbling for your wallet when you want a latte.Starbucks' mobile app, available for the iPhone and BlackBerry, allows users to essentially replace their Starbucks card with their phone.
Download the app, enter in your Starbucks card number, and your phone will display a barcode that can be scanned at the checkout counter. Users can track their balance on their mobiles, but the real selling point is the ability to order and pay quickly -- vital during a morning coffee rush. To reload the card, customers can link it to a debit, credit card or PayPal account
Starbucks started testing mobile payments in September 2009 in a handful of Bay Area and Seattle shops. On Wednesday, it expanded the effort to all 6,800 of its stores throughout the U.S.