Today, StumbleUpon unveiled a new feature that they call the “Explore Box.” Still technically in beta testing, the new feature allows users to search for specific topics to stumble, for example, Lady Gaga, William Faulkner, or Tequila. Until now, StumbleUpon …

Google has combined local search with personalized search, and social search to make a potentially powerful new kind of Google result that should benefit both users and businesses. These results come from a new Google product called "Hotpot", a recommendation engine designed for integration with Google Places. 

MySpace has announced an open source framework for "distributed computation," which is ultimately a recommendation engine. It’s called Qizmt, and it’s the feature the social network currently uses for its "People you may Know" feature.

"Qizmt can be used for many operations that require processing large amounts of data such as collaborative filtering for recommendations and analytics," explains MySpace COO Mike Jones.