At its annual F8 developers conference today, Facebook unveiled the company's latest effort to elevate social networking to an integral part of how people browse the Web.

Called Open Graph, Facebook's new effort is designed to merge users' preferences and data across multiple sites (or as the company calls it "social graphs"), as well as see what their other friends are into.

For instance, the Pandora Internet radio service is on of the 30 initial partners participating on the Open Graph system at launch. With it, Pandora now suggests artist-based stations by recognizing every artist users have "liked" on Facebook. It also allows users to see which of their Facebook friends like the same bands, as well as see what other artists those friends have selected. Going further, Pandora users' Facebook profile information populates their Pandora profile so that all their friends lists are instantly merged.

As part of the same effort, Facebook is adding "Like" buttons to partner websites. The "Like" button on Facebook allow users to indicate their approval of friend's updates, photos, etc. and have that approval added to their updates. The new feature will let users "Like" a story on CNN, or a band on Pandora. And if added to third party sites or services (such as iTunes or individual band websites) the "Like" button would also impact Pandora recommendations. Facebook CEO Mark Zuckerberg, during his F8 keynote, explained this desire to merge activity on multiple sites.

"What we're going to do is make it possible to map those connections," he said. "Once it's possible to understand these connections, a lot of really neat things become possible. We can show you a news feed story when three of your friends all like the same restaurant. If you write a review, we can put that restaurant on your profile... We're going to connect all of those different graphs together to form the Open Graph, and when we connect all of those graphs together, the Web is going to get a whole lot better."

Of course all of this means Facebook is at the center of that shared experience, and concerns are already bubbling about the privacy implications that will have. The move closely follows the strategy started with the 2007 unveiling of Facebook's application development platform and the 2008 addition of Facebook Connect.

In other Facebook news coming out of F8:
- No update on the virtual currency system, called "Facebook Credits." More than 100 Facebook apps currently participating as beta testers of the new system, but it's not yet open to the public and there's no indication when it will. Setting up a virtual currency system on Facebook is considered important to app developers who want to sell goods both virtual and actual. Once users sign up to the credits program, they won't ever have to enter their credit card info again other than updating it. Purchases instead can be made simply through the system, with Facebook taking a 30% cut.

- Zuckerberg kicked off the conference Steve Jobs-style with some milestones, noting that Facebook has more than 400 million users worldwide, with 100 million on Facebook Mobile. Ten of the top 10 iPhone apps are linked into Facebook Connect, which also has 100 million users.