Somethings I have learned just by being a little more observant. One day last week I was sitting at a different table than usual at school, and it happened to be next to the bulletin board. At the very top of the bulletin board was a flier that I had never seen before that had a list of two websites, one of them being Math Applets for Calculus at St. Louis University. Personally, I have never been too big of a fan of applets, but most of these are really great. There are four types of applets there: JCM Applets, Banchoff Applets, Geometer's Sketchpad Applets, GeoGebra Applets.
However, I was actually more interested in GeoGebra than the actual applets, since I had never heard of it before. It turns out that GeoGebra is a free tool to create learning and teaching materials. I played a little bit with the web-based version since I didn't really want to download anything that I wasn't so sure about. And now I can see that it is a terrific resource that I will be using well into the future. Of course, although I also like the Wolfram Demonstrations Project, I can't get over the fact that you need the Mathematica Player in order to be able to show the demonstrations in class. And since I don't have the rights to download it in many of the buildings that I teach in, sometimes it is a fail for me. GeoGebra is different since I can put the Applets directly onto my own webspace.
As a great introduction to using GeoGebra, I highly recommend checking out the video below, which will give you just a small taste of its power and might. By the way, the guy in the video says GeoGebra incorrectly every time. It's GEE-AHH-GEBRA, not GEE-O-GEBRA. I found this out only because I watched another video from the creator of GeoGebra. Sorry, just a pet peeve, just like when students pronounce EULER incorrectly.