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Peter Thiel, 40
Peter Thiel, 40
Founder's Fund

Having hit the jackpot as co-founder of PayPal, Thiel wears many hats. His hedge fund, Clarium, racks up stellar returns. His VC firm got in early on Facebook and other companies like Slide and Yelp.

NEXT: Danny Rimer, 37
Last updated July 19 2008: 2:17 PM ET
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