Wolfram Alpha
Perhaps you’ve heard of Wolfram Alpha (or WolframAlpha or Wolfram|Alpha or however it’s bloody written.) Perhaps you haven’t.
Early hype suggested it would make Google look as relevant as a Soda Stream. I don’t know if that’s going to be the case.
You see, it’s not really a search engine; more an engine that’s on the web. Indeed, the boffs at Wolfram Alpha call it a “computational knowledge engine”. It’s not about returning the most relevant page in relation to your search, more about giving you answers to questions.
I used it to work out that I’m 10,000 days old on 30 August, 2009. Which is cool and petrifying all at the same time.

You can also use it to calculate mortgages.
Powerful, clever stuff. Read more about it here.