Google is working on an update called Caffeine, which will increase the speed at which it indexes content. This could be a step toward Google’s incarnation of real-time search. Facebook has just started rolling out its own real-time search feature, much like Twitter’s, which has been around for some time.

Earlier this month, Bing began to return certain celebrities’ most recent tweets on its main results pages.  Now, a side project has taken the real-time search integration much further, with BingTweets turning up all sorts of Twitter-related info together with a more standard set of search results.

BingTweets, which is in beta, is a result of a partnership between Bing, Federated Media, and Twitter.  The most interesting thing about it is that users can see a constantly-growing list of tweets in which their query term features.