Collecta is a new real-time search engine that taps into Twitter, Flickr, blog comments, and news sites--all at once. Users are able to quickly filter which sources they want to search from, and can leave multiple searches running continuously, so that the latest content keeps rising to the top.
What I really like is that you can just leave it running in the background, and come back to check on searches throughout the day. I often do the same thing with TweetDeck with Twitter searches, but what's nice about Collecta is that it's grabbing search results from multiple sources.
Another nice feature is that you can preview most types of content without leaving the results. This is more useful for photos and blog posts than messages from microblogging services like Twitter, Jaiku and Identi.ca--the three it culls from. It also only captures images from Twitter, but I expect it to add more in the future.
Where these tools still have a ways to go is in weighing content from certain sources more heavily than others, and helping to weed through some of the duplicate entries. Competitor OneRiot does a good job at this by choosing relevancy based not only on time, but the results that have been shared more heavily among other users at a specific source.
Note: At the time of publishing this post, the site is no longer functioning correctly. When I began to use the service right after its launch it was coming up with results almost instantly, and now it's just continuously searching without showing any results. Since I've seen it work so quickly, I'm willing to put it up to some launch jitters, but you may have to wait until later in the day to give it a proper go.
See also, which was made by the former head of Microsoft's search unit.