If you have not heard about this it is really a cool story. Phil Venditti teaches public speaking and he took a sabatical from his day job at Clover Park Technical College in Washington state to create this group of 50 videos of prominent public speakers. These are now open content for use with many different types of classes for this subject. There is a great piece on this at Creative Commons - http://creativecommons.org/weblog/entry/42373 but you can check out the videos on Phil's YouTube Channel.