Starbucks just launched two iPhone apps. One app, myStarbucks, allows users to find stores, build drinks, and browse the coffee chain's menu and find nutritional information. While this is interesting, the second app is far more exciting. Starbucks Card Mobile gives users a virtual Starbucks Card and in 16 select stores in Silicon Valley and Seattle, users will be able to use this app to pay for their drinks. The app will display a barcode that the baristas at these stores will be able to scan.

In addition, the mobile payment app will also allow users to check their card's balance, reload it with any major credit card, and view their transaction history. For now, this feature will only be available in these two test markets, which, according to Starbucks, were chosen because of the high usage rates of iPhones and Starbucks' loyalty cards. After this trial, Starbucks will decide whether it will bring this feature to other markets.

While similar and more sophisticated payment schemes that use mobile phones have already become relatively widespread in other countries, the US is still lagging behind, though some interesting mobile payment projects have already made it to the market. Just last month, Nokia announced its Nokia Money service, but it remains to be seen if this service will be able to gain any traction.

Starbucks, on the other hand, already has a large user base for its Starbucks Card and given that customers have to use their card to get access to Starbuck's Wi-Fi network, customers already have a pretty strong incentive to use the card and the app.