Data is everywhere, it doesn't matter what you teach, you need data and researching the web is a fast and great way to do it. Sometimes, we don't always get what we want.
If you have not tried it, enter 5 pounds to grams in Google. The effect is even cooler because of Google Instant. Or try entering 60/2.5. For all that Google can do, it is also a great calculator or conversion tool. In fact Google is able to do all kinds of helpful things besides just searching for websites (link)
Yet, try entering y=2x+5 and you will receive websites that may help you understand linear equations or maybe eventually show you the graph but this isn't exactly what you meant. What if you are researching different countries and comparing demographics? England and China, England vs China, no matter what you try, you will still need to root through search results.
WolframAlpha.com emerged on the scene. Developed by Stephen Wolfram and his colleagues, it touts itself as a "Computational Knowledge Engine". For those of you familiar with Stephen Wolfram's previous work with Mathematica, the website is powered by the same algorithims.
Try it out or look at some of the examples. I honestly, could spend a lot of time going through each one. They are just so beautiful and helpful. Going to our original examples, go to WolframAlpha.com and type in y=2x+5 and hit enter. There is the graph you were looking for. WolframAlpha.com is a full fledged graphing calculator.
Now try England vs China. This will not pull up sports scores or obscure websites with those keywords. You are presented with a useful side by side comparison of the two countries' demographics, landmass, etc.
I enjoy typing in my name as it will tell me how many others of me there are in the world. The examples are certainly worth your time. Click around and see the possibilities of seeing data in a way that is truly useful. This isn't surprising from Stephen Wolfram who has spend a great deal of time and energy trying to make the world's knowledge not only searchable but computational. Data is worthless if we cannot work with it and that is exactly what Mathematica and Wolframalpha.com were intended to do. You can see more of Mr. Wolfram's philosophy in this TED talk where he draws from his research and writings in A New Kind of Science.
In an effort to make Wolfram Alpha more accessible, others have implemented this in Firefox, and Chrome, (free) and now Android, iPhone, and iPad (for $1.99).
Two other free options for educators are Wolfram Alpha Demonstrations, and Widgets. Demonstrations are similar to the examples, but with a large amount of interactivity. Show your students a physics or math principle, art and color, sports examples, optical illusions, and more. Widgets are an option for you or your students to create your own mini Wolfram Alpha program. It is easy to create one to add to your website or for your classroom, there is also a gallery of premade widgets.
Whether you teach the humanities or sciences, WolframAlpha has the power to make data managable and useful. If you haven't already go over to the site and browse you will find it hard to leave.