Microsoft have just acquired Powerset, a natural-language search startup from San Francisco. If you're a fan of Wikipedia (which I am), then I suggest you give Powerset a try!
Powerset’s goal is to change the way people interact with technology by enabling computers to understand our language. While this is a difficult challenge, we believe that now is the right time to begin the journey. Powerset is first applying its natural language processing to search, aiming to improve the way we find information by unlocking the meaning encoded in ordinary human language...more here
I recommend watching the embedded video to see how good this really is.
Powerset Demo Video from officialpowerset on Vimeo.