Wolfram Alpha is probably the most useful site on the internet.

It's not a search engine, it's not an encyclopedia, and it's not a calculator, but it's a little bit of all of that. It's really the only member of its field.

Originally developed as an online version of Stephen Wolfram's Mathematica software, its basic functionality is that of a math equation solver.

Over the years, however, it's grown substantially, and has really matured as a site to become one of the coolest and most informative sites online.

Here are some of the coolest things you can do with it.