Looks like there is some momentum building to integrate GeoGebra applets into the Sage notebook, which I think would be fantastic. I've been lazy about checking out GeoGebra until now, despite hearing good things about it. Dan Drake's demonstration of a nice applet made in less than an hour of experimenting inspired me to give it a try. In ten minutes I had downloaded GeoGebra, installed it, made a simple demo and moved it to my university account. I am very impressed, and hope to help a little to get this into Sage.