Khan Academy

This was one of the best websites I have found yet. It deals mostly with math buthas history, biology, chemistry, and economics videos as well. It basically has a cache of videos that explain a multitude of concepts, mostly math. I think I could use this in a math class introducing a concept, such as multiplying integers, and the video explains it in simple terms. I found it very useful and the explanations are clear and also gives ample examples for the students to practice while they watch the video. I could see myself using this in the classroom for math.