Tim Ferriss, author of the bestseller The 4-Hour Workweek, has written a new book, The 4-Hour Body, for which he spent three years experimenting with fad diets, workouts, and medical treatments. "I made myself a guinea pig," says Ferriss. "It was terrifying, exciting, and illuminating."...PayPal co-founder Peter Thiel has established a one-time fellowship that will award $100,000 grants to 20 aspiring tech entrepreneurs under 20. Thiel sees his grants as alternatives to college. "Some say I shouldn't encourage students to drop out," he says. "But many students graduate with huge tuition debt, which can stop them from being entrepreneurial."...Speaking of fledgling entrepreneurs, Stephen Ou, a high school freshman in San Leandro, California, recently launched iTunes Instant, a website that speeds up searches of Apple's iTunes store. "I usually finish my homework at school so I can focus on my side projects at night," says Ou, whose site had roughly 100,000 hits in its first three weeks....Kelly Ripa has teamed with TLC to create Homemade Millionaire, a reality show that features Ripa helping aspiring female entrepreneurs market their wares on the Home Shopping Network....Caleb Elston recently left a job at Justin.tv to focus on his own start-up, Yobongo, maker of a mobile app that lets users text others nearby. "Working for other people's start-ups can be great, but ultimately the vision isn't yours," says Elston.