Wolfram|Alpha is finally launched! Wolfram|Alpha is a computational knowledge engine that to interpret the questions/queries and tries to formulate answers. It is not a search engine, it is a combination of encyclopedia and real-time data mining. Wolfram|Alpha tries to structure the information scattered in world wide web. It could be great for scientific (physics, mathematics etc.) queries as it uses Wolfram Mathematica to compute answers. It is still in alpha stage and has a long way to go. Try it out!
By the way, Wolfram|Alpha has answer to life, the universe, and everything. It's 42 ;)
And, you will see this when Wolfram|Alpha website traffic exceeds its bandwidth limit:
Google is working on a similar tool called Google Squared, which aims to structure the unstructured information.