I just found out about WolframAlpha, and I'm wishing that I had all day to sit here and play with it.
Alas, I don't, but I can share it with you. First, watch this tutorial. Then play. It looks like a very, very powerful tool for all sorts of disciplines. It's simply amazing that there are people who can take the sum of human knowledge and make it searchable. Wow.
They're going to need a catchier name if they're going to out-Google Google, but they're off to a great start! Amazing.