It may take two to tango, but payments now are as easy as one touch. Four Carnegie Mellon University seniors tired of digging through backpacks, pockets and purses for their student identification and debit cards have developed PayTango, a fingerprint-based identification and payment system. With majors ranging from information systems and human-computer interaction to industrial design, Brian Groudan, Kelly Lau-Kee, Umang Patel and Christian Reyes combined their expertise to launch their startup. "We believe you should be able to walk into any establishment and prove who you are without carrying anything — no apps, no cards," Groudan said. "PayTango can be used for everyday activities like paying for a morning coffee or critical scenarios like identifying patients' medical information in a hospital." The startup is attracting attention from media and potential investors. Inc. magazine recently named it among " America's Coolest College Startups" for 2013. PayTango's registration process takes about 20 seconds. Users place two fingers on the terminal's fingerpad, swipe the card they want to register and type in a phone number. Any card with a magnetic stripe can be registered in the system, including credit, debit, gift, loyalty and identification cards. On repeat visits, users simply place their fingers on the fingerpad to make a payment. The service is paid for through contracts with merchants, making it free for users. The students developed PayTango in the fall of 2012 in the inaugural Tech Startup Lab course of School of Computer Science Assistant Professor Luis von Ahn, creator of startups reCAPTCHA, which was acquired by Google, and Duolingo. After winning three awards at the University of Pennsylvania's PennApps hackathon in September, the team applied to and was accepted at the Y Combinator startup accelerator in Mountain View, Calif. Three members of the team moved to the West Coast in January for the three-month program, which culminates in a Demo Day for investors today ( March 26). Back in Pittsburgh, PayTango pilot-tested its terminals in partnership with CMU's Dining Services at one campus location in February. The company expanded to three dining locations in March and opened enrollment to all students signed up for a university meal plan or one of the flexible dollar programs. "PayTango sparked our interest, because it fits into the innovative and entrepreneurial tradition of CMU students," said Michael Baux, director of Dining Services. "PayTango is user friendly, easy to enroll and transparent to our staff's regular process at point-of-sale systems. Students are intrigued about the payment system but are even more excited when they find out PayTango is from their peers." The company is expanding to gyms, which could replace membership cards with the fingerprint technology. Within the next year, the team also hopes to launch on other college campuses and at a variety of retailers.