Prominent venture capital fund Andreessen Horowitz has confirmed earlier rumors that it has raised a $650 million fund, less than a year after it raised its first $300 million fund.

For Netscape buddies Marc Andressen and Ben Horowitz, that means they will be busy pouring a lot of money into Silicon Valley startups. For those already in the firm’s portfolio, it likely means future rounds of funding will be in the cards.

Techcrunch reports that the fund now has an investment staff of 18 and a portfolio that includes Skype, Zynga and Foursquare. The two men are in the unique position of being entrepreneurs who have sold two companies for more than $1 billion each (Netscape and Opsware). Andreessen sits on the boards of eBay, Facebook, and Hewlett-Packard. You can’t really get more A-list than that.

Hopefully, these guys will be able to get into any fancy restaurant they want now — though we suspect Andreessen will keep showing up in his beloved Hobee’s. Either way, these folks are becoming some of the most powerful kingmakers in Silicon Valley.

Horowitz said the fund isn’t larger because they didn’t want the size of the fund to dictate the pace at which they make investments. They would rather go raise money again if things go well than have to rush to find good deals because they have too much money to invest, he said.