I just read this whole article and am very excited about it. From VentureBeat:

A Silicon Valley company with a noteworthy founder has created a mobile payment system called FaceCash that it hopes will one day displace credit cards.

You might be tempted to write this off as too audacious. But consider this: The founder is Aaron Greenspan, the Harvard graduate who claimed in 2007 that his former schoolmate, Mark Zuckerberg, ripped off his work when Zuckerberg created Facebook. Greenspan settled a trademark lawsuit with Facebook and Zuckerberg filed in 2008 last year.

Greenspan, now 27, exudes not only intelligence, but also a quiet, steely determination: He has been working on his payment technology for about ten years now, since he was managing the accounting technology for his family’s business. Oh, and how would you feel if your college rival went on to build what some people say is a $20 billion company,  based on your work? You’d be on a hardcore mission to somewhere, too.

Greenspan demonstrated FaceCash today for VentureBeat, by using it to demonstrate how he could pay for a lunch he had at the Indochine Thai restaurant in Palo Alto, Calif. (See videos below for short demo).

Here’s how it works: You can download the FaceCash application on any leading smartphone — it will be available on iPhone, BlackBerry or Android phones beginning next week. Then you type in your bank account information, Social Security number, and driver’s licence number, and upload your picture. That’s it. You can now use your phone to make pretty much any in-person transaction, whether at a restaurant or at a grocery store — as long as the merchant has signed up for the service. To accept your payment, the merchant simply scans the FaceCash barcode on your phone with a scanner, and your picture will pop up on their computer screen — which helps them avoid fraud. They then approve your payment. Dead easy. And slick.