Let me start with this gem:
1942 Disney video on methods of flush riveting
http://www.youtube.com/watch?v=IagmAgHvcWQ
and add a recent find:
1961 Department of Defense - DC Motors and Generators
http://www.youtube.com/watch?v=OpL0joqJmqY
1930 Mechanical Principles by Ralph Steiner
http://www.youtube.com/watch?v=mkQ2pXkYjRM short version
http://www.youtube.com/watch?v=Y5pen3QMgzQ full version
Post up any other favorites
