Wolfram Alpha may be a data geek's dream, but if you're not all that interested in its more obscure uses, here's one thing we could all use a little help with: step-by-step math calculations.
Just enter in the equation you want solved (say, for example, Solve 2x3 - 6.543x = x2, then click the Show steps link to see how you could solve the problem yourself next time without the help of Wolfram Alpha. It'll then walk you through all the steps necessary to reach your answer. TI-85, eat your heart out.
Step-by-Step Math [Wolfram Alpha Blog]