I just found this on a homeschool website, this is really an awsome tool.
If you download the veoh player, you can search for example "The Magic School Bus", and it has 50 free full length episodes. I figured it was worth downloading the player just for the the episodes.
Here is the link to download the player:http://www.veoh.com/veohTV/getStarted.html
You can find tons of different channels that offer free videos on it, PBS, NBC, CBS, DIY and tons more. You can also do a search for contents of the videos, if you are looking for a specific subject. My kids LOVE The Magic School Bus and now they have tons to watch. It's worth the download for sure.