College lost-and-founds are packed with misplaced phones and wallets, leaving their owners stranded. But what if, imagined Brian Groudan, Kelly Lau-Kee, Umang Patel, and Christian Reyes, students could pay for meals, access dorms, and never worry about carrying--or forgetting--anything?

Together, the four students created PayTango, a payment system that identifies users by their fingerprints. To register, users touch two fingertips to a screen, swipe the card whose data they wish to associate, and type in a phone number--a process that takes about twenty seconds. At subsequent visits, users can simply touch the screen to call up their card information.

"We wanted to solve the problem of all these cards you have to carry around and things you need to identify yourself--there had to be a better way," says Patel. "We realized biometrics might be the best way to solve the problem of keys and credit cards."

Friends since freshman year at Carnegie Mellon University, the students brought a powerful arsenal of skills to their collaboration with majors in Information Systems, Human Computer Interaction, Business Administration, and Industrial Design. After developing the idea and building their prototype through a series of hackathons and a class with crowdsourcing trailblazer Luis von Ahn, the students were accepted into Silicon Valley accelerator Y Combinator, which provided them with seed funding and access to capital from firms including Maverick Capital and Start Fund.

In January 2013 Groudan, Patel, and Reyes moved to Mountainview, California, to work on PayTango full-time. All four students plan to gradudate in May.

Back at Carnegie Mellon, PayTango’s impact has already been felt. The service is being used in place of traditional payment swipe cards in several of the university’s dining halls, and over one hundred students registered with the service within the first four hours of its launch in early February.

The service, which is paid for via PayTango contracts with merchants, is free for users.

"The idea that you are not carrying around something that gives you access to your money--it’s something that you have, something that you are. You can roll out of bed, forget your wallet, and still be able to make a transaction," says Max Hawkins, a fellow Carnegie Mellon senior who works with other student-run start-ups at the Frank-Ratchye STUDIO for Creative Inquiry at CMU.

Over the course of the next year, PayTango’s founders are hoping to launch the service on different college campuses and contract with other merchants and retailers that require members carry a unique ID card, like gyms. In the future, they envision replacing credit and rewards cards as well.

"The thing that we do differently is easy enrollment," says Patel. "You don’t need specific technology and you don’t have to carry anything around with you. It’s just a more seamless approach."