SM-YT

Me!
There is only one!

 [|http://www.youtube.com]

 But there is also....

 [|http://www.teachertube.com]

(Videos of, by, and for teachers for sharing instructional videos. TeacherTube provides teachers, schools, and home learners an educationally focused, safe venue to upload, tag and share videos worldwide; attach support files such as assessments, lesson plans, and notes; browse hundreds of videos uploaded by community members; find, join and create video groups to connect with people who have similar interests; customize the experience by subscribing to member videos, saving favorites, and creating playlists; integrate TeacherTube videos on websites using video embeds or APIs; make videos public or private; and more).

Recently, SmartTeaching.org published (on their blog) a "100 Best YouTube Videos for Teachers". I have my personal favorites that aren't in the list and some they have I would not include, but it is certainly worth a look:

[|http://www.smartteaching.org/blog/2008/08/100-bnest-youtube-videos-for-teachers/]