How Stuff Works

Japan's Attack At Pearl Harbor
How Stuff Works
This is a great site for many reasons, mostly because they have hundreds of short videos (on many things beyond the classroom). I have found it very good for both US and world history. Above, for example is the bombing of Pearl Harbor. The coolest thing is that the movies are 3-1o minutes, so if a student misses class, he/she can still see what you watched!