Reid Hoffman is kind of like the Zelig of technology, but instead of a mere observer, he has participated in many, many major tech events. He started his career at Apple in 1994, and founded SocialNet.Com, a social network years ahead of its time. He was an EVP at PayPal before founding LinkedIn. He introduced Peter Thiel and Mark Zuckerberg. He's a partner at Greylock Investments, one of the most established VC funds.