Jim Clark
Then: Serial entrepreneur Clark started Silicon Graphics, a transformational 3-D imaging company, and later co-founded Netscape with Marc Andreessen. The browser company's IPO in 1995 kicked off the dot-com boom and made Clark a billionaire.
Now: Clark directs his money and energy toward saving the oceans. He started the Oceanic Preservation Society with photographer Louie Psihoyos and provided funding for his Oscar-winning film "The Cove," a documentary about the Japanese slaughter of dolphins.
Clark is also working on a product that automates power consumption in the home.
Clark worries about the future of science in the U.S. and is dismayed by how many bright college graduates go into finance. "It spells doom for the country," says Clark, 67. "I look at how hard I had to work to make a couple billion. And I see these guys making that in one year betting with other people's money. There's just something crazy about it."
By Ellen Florian
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Last updated October 28 2010: 8:20 AM ET
