* ANNENBERG MEDIA has videos on all subjects. I have to explore this, but it looks like great complements to things like science, math, literature...worth to type what you are learning about to see if there is a video to watch.
Some sites for GEOMETRY:
* THE EYE BALLING GAME
* ENOUGH OF EUCLID
* GEOMETRY GAMES AND RESOURCES ONLINE
* MATHSNET (GEOMETRY SECTION)