The first place website I go to when looking for a video in the math classroom is http://www.thefutureschannel.com/. These videos take real life situations and show how math and science play a part in everyday activities. The following is a video on inventing toys: http://www.thefutureschannel.com/dockets/realworld/inventing_toys/
I tend to find that a lot of the math videos are basic "how to" solve math problems videos. Which tend to be pretty boring. Anthother great site to go to for math videos is http://science.discovery.com. Here is one on Pythagoras. http://science.discovery.com/videos/what-the-ancients-knew-pythagoras-the-music-and-math.html
"Winnie Cooper" loves math!