Kleiner Perkins Caufield & Byers announced today the sFund, a $250 million initiative set to invest in social web entrepreneurs. At the announcement today at Facebook headquarters, KPCB's John Doerr and Bing Gordon were joined by partners in the fund, Facebook's Mark Zuckerberg, Zynga's Mark Pincus, and Amazon's Jeff Bezos.

The sFund will provide capital and counsel for "a new generation of entrepreneurs to deliver on the promise of the social web."

Although KPCB has been one of the most successful players in the development of (or rather, investment in) Internet technologies, it has been seen as the "old guard" lately, and there have already been a number of commentaries today about John Doerr's decision to appear at the announcement in jeans and a hoodie as an attempt to maintain the VC firm's " relevance."

"We're at the beginning of a new era for social Internet innovators who are re-imagining and re-inventing a Web of people and places, looking beyond documents and websites," said Doerr in the press release. "There's never been a better time than now to start a new social venture."

If this is just the "beginning of a new era," then the timing of the fund is great. But arguably (actually, I'm not even sure it's arguable), the era of "social" is well underway.

Nevertheless, today's announcement makes clear that investment dollars are set to follow where Internet users' activities seem to be headed. And that is in the realm that Facebook and Zynga - supported by the Amazon cloud - dominate. And KPCB's interest in the sector confirms that VCs see big money - big exits - in the future of social.