Yahoo has come up with something new called "Instant Search" and here are the details from the Yahoo Blog:
sometimes there is one really good answer to your search. And that’s what led us to develop Instant Search, which went into beta today on our next.yahoo.com site. As you type your search into the Instant Search box, it checks to see if there is a single, relevant answer for your query. If there is, that single result instantly appears on the page, just below the search box in a kind of "speech bubble". You don’t even have to hit the Search button or the Enter key, and you don’t have to sort through pages of results (though of course that option is still available to you).