The Live Geometry project is “A computer model of plane geometry that allows you to create interactive ruler and compass constructions and experiment with them.” Looks very cool to me. I can imagine lots of ways for teachers and students of geography to use this in constructive ways. This is the kind of tool that I think we need more people developing. Everyone learns more by doing and if we can make “doing” easier and more fun and keep it real and educational everyone benefits.
You can see an online preview at http://geometry.osenkov.com The author’s blog is at http://blogs.msdn.com/kirillosenkov and you can read his announcement here. Kirill’s pages have much better screenshots because he actually knows what he’s doing in geometry.