Useful Links

Youtube
YouTube is the leader in online video, and the premier destination to watch and share original videos worldwide through a Web experience.
http://www.youtube.com/

Savevid
Savevid.com is a tool which gives you the ability to download videos from streaming video sites. 
http://www.savevid.com/

Keepvid
Keepvid helps you download and save videos directly from Youtube, Google, Metacafe, Putfile and more
http://www.keepvid.com/