Third consecutive day of just general science/math goodness links... wolfram.com are the people who write and sell the world renown computational algebra system Mathematica (http://www.wolfram.com/products/mathematica). Most of the people who work on mathematica started out as either physicists or mathematicians.
Mathworld is a great place to poke around and learn math in a very "quick reference" way. Think of mathworld as a nice starting point). It also has nice general (and not so general) explination/definitions of physics terms and overviews historical physics experiments.
Did I also mention it has lots and lots of perdy Mathematica rendered eyecandy?
[Math is beautiful - Nano]