YouTube is one of the best online education sites on the Internet. The problem has been that YouTube is also filled with every kind of video, from sublime lectures by some of the great minds of the century to the bone snapping stunts of marginally sane teens, to the grungy mumblings of the fringe. It's like much of the Internet: a mixed bag of nuts with some real gems if you know how to find them.
Many school districts ban the use of YouTube because it is easier to just say no and cover your liability than spending the time to evaluate content and use a great resource the kids already have after school (and on their phone) access too in the first place.
YouTube has taken steps to create a safe silo of content for teachers everywhere. Other services like TeacherTube and Schooltube have been providing this service as well.
Let's hope that creating YouTube Teachers (http://www.youtube.com/teachers) will make it easier for someone in a district office to punch the filter button and let the video stream.
10 Ways to use YouTube in the Classroom