Relevance meets the real-time web is name of the blog post, where Google explains its Real Time Search.
And, as part of our launch of real-time on Google search, we’ve added “hot topics” to Google Trends to show the most common topics people are publishing to the web in real-time. With this improvement and a series of other interface enhancements, Google Trends is graduating from Labs.
Our real-time search features are based on more than a dozen new search technologies that enable us to monitor more than a billion documents and process hundreds of millions of real-time changes each day. Of course, none of this would be possible without the support of our new partners that we’re announcing today: Facebook, MySpace, FriendFeed, Jaiku and Identi.ca — along with Twitter, which we announced a few weeks ago. (source)
Google Real Time Search