Wolfram, the maker of Mathematica and other software, came out with a "computational knowledge engine" a couple of years ago. It's an extremely useful website which allows anyone to quickly and easily obtain a huge variety of facts. Check it out: http://www.wolframalpha.com/ When showing this site to students, I often start by typing in "GDP of United states/ GDP of Canada" and "sin(x)+cos(y)."
If you want to read more about what this technology is useful for, check out this MAA article: http://mathdl.maa.org/images/upload_library/23/karaali/alpha/index.html or WolframAlpha's own set of examples: http://www.wolframalpha.com/examples/
