WolframAlpha was just recently released, and it's taken me a little while to get my head around this. The description on the site reads "computational knowledge engine," and it looks like an amazing step towards having a website yield answers rather than search results. So instead of entering a search term, you enter data or a question, and WA attempts to compute and answer the question. Here are the details from my test drive.
Type "winston salem" (below) and WolframAlpha quickly delivers data about Winston-Salem.
Type in "winston salem weather"(above), and you'll receive an amazing amount of information about the current weather and how it compares to the data readings from past Winston-Salem weather.
Try plugging in your height and weight, and WA will give you data about BMI, basal metabolic rate, body fluids and typical organ properties.
Finally, type in a question and WolframAlpha will try to answer it. If your query doesn't include enough information, you'll get "Alpha isn't sure what to do with your input."
However, you might be surprised what WA will answer (see below).
So WolframAlpha is great at delivering a wealth of data on a subject or answering a question with amazing speed. This could be a huge step in the ways we (and students) interact with technology. And it's even friendly. . . sort of.