Facebook has been granted a patent called "Ranking search results based on the frequency of clicks on the search results by members of a social network who are within a predetermined degree of separation". Here’s the abstract:
Search results, including sponsored links and algorithmic search results, are generated in response to a query, and are marked based on frequency of clicks on the search results by members of social network who are within a predetermined degree of separation from the member who submitted the query. The markers are visual tags and comprise either a text string or an image.
It is unclear whether or not Facebook will actually do anything with this patent, but search will continue to become more important to Facebook. That much is clear, as mroe objects, places, and businesses become connected to Facebook.
Nick Saint at Silicon Alley Insider suggests that Facebook could "use this patent as a weapon" against Google if "Google Me" becomes a threat to Facebook.
The patent was filed all the way back in 2004. You can take a look at the entire thing here. (hat tip to GoRumors)