The first is a brief video with music by Patti Smith.
The second is somewhat humorous about a student asking him not to run for office.
The third video is actually part 5 of 5 on YouTube, of an extra feature on the DVD of An Unreasonable Man, a documentary about Ralph Nader. This was a documentary I first saw on PBS and purchased the DVD. This segment has a few great points to it, namely of a political consultant who worked for the Democratic Party for years. He points out that to vote for someone you don't believe in makes you a politician, not a voter.
All of these videos and more can be found at the VoteNader08 page on the YouTube web site.