Collecta
Collecta monitors the update streams of popular realtime blogs and sites like Twitter, Wordpress, and Flickr, and shows results as they happen. Results can be filtered by status updates, comments, stories, or photos. The entire engine is built around the XMPP standard, which pushes out data on a continual basis, so that for every search you end up watching a stream that keeps updating itself.
UPDATE: Collecta is now offering a API and chance to win a MacBook Pro!. Developers can use the Collecta REST API to create an applicatioin that receives fresh stories, posts, pictures and video from across the web as they're published. For extra-easy implementation, the API format is very similar to the Twitter Search API.
You can also find them here: