Teacher Tube
From the website: " TeacherTube community members are a major part of the evolution of the site. Members are encouraged to not only upload educationally relevant videos, but also to make constructive comments and use the rating system to show appreciation for videos of value to one as an educator or learner. Users also have the ability to preserve the integrity of the site by flagging inappropriate videos. TeacherTube staff review flagged sites and will remove any inappropriate posts. With more collegial commentary and discussion through messaging and responses, the quality of this resource will only increase.
The service is free for everyone."
The website has very simple and effective organizational method for its resources, which are searchable by topic, format, or grade level.