Future of mobile commerce, in a skinny vanilla latte?

Your decaf caramel macchiatos and no-whip pumpkin spice lattes are going mobile.

In a double-shot launch (sorry), coffee giant Starbucks unveiled late Tuesday its first two iPhone apps. The first one, called MyStarbucks, is a no-brainer: you can use the phone's GPS capability to find nearby stores (previously, this was available via text message), search ingredient and calorie information for Starbucks beverages, study coffee bean varieties, and build virtual drinks to see what exactly would be in one if you ordered it.

But it's the second app, called Starbucks Card Mobile, that could be worth a double-take. The app allows for balance check and refilling of Starbucks gift cards, which the company has expanded into a customer loyalty program by offering discounts, free refills, and two hours of free Wi-Fi to cardholders. And in two experimental test markets, the Starbucks Card Mobile application can use a barcode to replace the plastic gift card altogether.

As far as mobile e-commerce is concerned, this could be a big deal.

Mobile retail promotions, from text-message codes to redeem for free drinks to the nascent pop-up deals in geolocation app Foursquare, are nothing new. And mobile payments are commonplace in countries like Japan and South Korea. In the U.S., they haven't caught on yet. But having a ubiquitous national retailer like Starbucks in the game could change this.

"We're really venturing into new waters in terms of mobile payment," Stephen Gillett, senior vice president of digital ventures at Starbucks, said regarding the Starbucks Card Mobile app.

"The mobile app is really the powering of some of our most frequently used functions on (the Starbucks card's Web site) and our in-store activity in terms of balance and payment and favorite orders," Gillett said. The app was developed internally with some help from third-party companies like mobile billing start-up mFoundry, he said.

Unless you're geographically very lucky, you won't be able to pay for a venti frappuccino with your iPhone just yet. Only 16 Starbucks outlets, eight in its home turf of Seattle and eight in Silicon Valley, can currently handle the barcode-based gift cards. These are stores already internally designated as test spots for new Starbucks technology, Gillett said.

"In some of these Seattle stores we've tested store manager laptops, allowing them to get instant messaging, full access to e-mail, and conferencing," he said. "These are some of the stores that got the new AT&T Wi-Fi earlier."

As a result, that means the integration process may be smoother for the test stores than it would be for a random Starbucks elsewhere in the country. "The store employees are used to getting new kinds of technology, new kinds of services earlier than most markets," Gillett said.

Estimates vary on just how big the U.S. gift card industry is, but according to the Federal Reserve, it's certainly well into the billions and continues to grow. As for Starbucks, already one in seven transactions at the coffee chain involves its array of gift and loyalty cards, Gillett says. "We see a significant amount of our traffic represented by loyalty cards of some sort," he said.

And eliminating that need for a physical gift card is a pretty obvious next step, especially if you've ever spent any time fishing around for one in a handbag.

The question is whether a new concept like barcode-based gift cards can easily scale to a chain as widespread as Starbucks. Mobile barcode systems have typically been rolled out in far smaller contexts--short-term advertising campaigns, for example, or companies with far smaller reach such as Equinox, a high-end gym in a handful of U.S. cities that recently began letting members check in with an iPhone-based barcode. And while Starbucks has been battered by the recession and has closed several hundred stores in the U.S., it still operates or licenses over 10,000 outlets in the U.S. and thousands more overseas.

So Starbucks is taking a slow approach to mobile payment testing, which means that customers outside of Silicon Valley and Seattle might not be seeing it any time soon.

"We're really working on getting that (customer) feedback before we put any long-term plans in future markets," Gillett said. "This really is a consumer-driven app in so many ways. This is an app that we need the customer experience to have a very strong influence on."

He was equally mum om whether Starbucks Card Mobile will offer advance mobile ordering options or other potential features. "Again, we're really looking to this app hitting the real world before we lock in future functionalities," Gillett said.

The same goes for taking the app beyond Apple's handset. Apple and Starbucks have a years-long and complicated history encompassing both iTunes and AT&T wireless service, but a mobile payment option ideally wouldn't be restricted to the iPhone.

"We are definitely interested in non-iPhone based platforms, particularly Windows and Android and BlackBerry," Gillett said. "But at this point we're just really focused on the launch for this."