Sam Altman, 22; Nick Sivo, 22
Mountain View, Calif.
Loopt co-founder Sam Altman remembers listening to his Stanford computer science classmates yammer away on their cell phones after class, discussing their whereabouts and hatching evening plans. Altman, who describes himself as a tech nerd who was always passionate about mobile technology, imagined there had to be a more sophisticated way to track down friends. He came up with the idea of creating customized mapping software for GPS-enabled phones, and dropped out of Stanford his sophomore year to turn it into a business.
Today, Altman and former classmate Nick Sivo run the business that allows users to locate friends on a map via cell phone or Web site. Altman expects the service, which costs users $3 a month and is available on various Sprint Nextel (S) networks, to be profitable by the end of 2008. Even though the 35-employee company has received $5 million in venture funding from New Enterprise Associates and Sequoia Capital and plans to expand to more carriers and handsets, Altman says: "I don't think of myself as a business guy. I think of myself as an engineer."