In all the commotion surrounding Microsoft's Bing, the demise of Yahoo Search, and Google's counter-attack by announcing a light-weight OS, something really useful to me, did not get as much play as it should have.
Wolfram Alpha is an amazingly intelligent search engine/parser/magic genie, for anything mathematical in particular. I have using it quite regularly, not quite as a substitute for Google yet, but even something as unthinkable as that could happen.
In the academic realm, it is a killer resource.
Here are just a few illustrative screenshots from my search today. You may have to zoom in a little bit for clarity.