Wolfram Alpha’s search engine focuses rather on calculating data entered by the user and displaying back results with useful stats. The premise behind the search engine is to work on calculations done to data, rather than searching for data on a large database.
I have used the search engine quite extensively since it was released, mainly to help me with mathematical calculations to check accuracy for my homework.
I have also used it “just because”, with random data, to test the system’s capabilities.
It is quite easy to use, intuitive, and fairly fast on the calculations and data search.
To visit it and test it out, go to http://www.wolframalpha.com