www.youtube.com/teachers

Google has launched YouTube for Teachers.  Whats different than YouTube is the way videos and subjects are organized, by classroom subject.  Also there are no adds.  At least that I could find.  This helps keep students on task and focused on the video that I want them to watch and keeps embarrassing adds from running or showing up next to a video.  I like this and I will probably sign up in the very near future.