President Barack Obama tapped John Doerr for advice. And so have countless hopeful business executives, programming whizzes and MBAs in Doerr's three decades as a venture capitalist at Kleiner Perkins Caufield & Byers. Doerr led early investments in household names such as Amazon, Google, and Netscape, as well as Zynga and the two-year-old $200 million iFund for iPhone developers. But technology start-ups are not the only thing near-and-dear to Doerr's heart. The VC also is passionate about green tech innovation, a "third wave" of disruptive mobile and social ventures, and is backing entrepreneurs working on global warming, job creation, public education, and global poverty/health, according to his company profile. Recently, Doerr informed the Amazon board that he would not run for re-election.