Schooltube offers various levels of accounts and channels for educators and schools. These range from free channels where teachers can post student videos, to premium channels and super channels. Each level gives you more features, including the ability to control your viewing settings (offering private, organization, or global viewing depending on your need for privacy), customize a banner, have unlimited storing space, and livestreaming.
http://vestaltech.edublogs.org/2011/06/04/livestreaming-in-education/