If you are mathematically inclined and are interested in numbers, give Wolfram|Alpha a try. It might surprise you.
Their objective is to provide information on your searches, not just a list websites that contain the text you are typing. They are not there yet, but there is a clear potentail. It runs on Mathematica, and is very good at solving mathematical problems, beyond your normal calculator extending to integrals and much more.
Just type “x^2 tan(x)” and review the results (image above).
If you are math geek or a math student or just someone interested in Math, check out there Mathematica player too. If you install the player, you can also download the results and view them in the player. Once the player is installed, Wolfram site has several demonstration projects that you can download and even get the source code if you are interested. Check it out if you get a chance.