"Kids Tube is a video sharing hosting and sharing site designed for hosting content produced by kids and content about kids. Kids Tube monitors all submissions and monitors comments left on videos. To encourage students to develop their videography skills, Kids Tube holds weekly videos submission contests. The contests are arranged around a theme and one winner is selected by the Kids Tube team." http://www.freetech4teachers.com/2010/08/kids-tube-monitored-video-sharing-for.html
They have over 500 Educational videos from School Rock - The Preamble to Great Composers.