WGBH is Boston's PBS affiliate. They have a wealth of educational videos on the internet that are available for anybody to download. Most of the videos were focused on science. The video I watched was targeted at high school students and was about the rise of homo sapiens and the extinction of Neanderthals. The video was taken directly from the show NOVA and was only 5 minutes long.
I believe videos like this can be extremely invaluable to a teacher. Even in college, it is difficult to hold attention in a class that is strictly lecture based. Educational videos provide another way to convey information. The videos on the WGBH iTunes site are professionally done. They can also be downloaded to a computer and viewed at any time. The main advantage of these videos is that they are a totally free tool that any teacher has access to. I could totally imagine myself finding some useful psychology videos on here and showing them to my future students.