Here's something cool from Chris Pirillo - type in an algebraic equation into MSN Search with a missing value 'x' and it will solve x for you. Observe what happens when you type in '2+4x=10':

Pretty cool, I think you'll agree. Still, it hasn't implemented the equivalent of Google's calaculator, so I can't type in "2 pints in litres" and find the result like I can with Google.

Ack it even solves (polynomial) equations!
http://beta.search.msn.com/results.aspx?q=x%5E2+-+4x+%2B4+%3D+0