Years ago, we had a high profile engineer nail his resignation onto a 2x4, which he in turn nailed to the door of a VP that he had, uhhh, differences with. The significance of the 2x4 is, if I remember the story correctly, it was given to him by a customer and had something inscribed to the effect of thanking him for quality work on a release or feature or fixing a nasty bug. And the disagreement with the VP had something to do with him feeling that the emphasis on quality was being shoved aside.
I also still have an email that I'm pretty certain was sent by him after he left, "signed" by our CEO (but obviously mailed via anonymous remailer), saying he was terminated for unacceptable conduct, including calling one of the corporate officers a dickhead.
Not sure how much of this is true and how much legend but people who worked with him say it is true.
Funniest part is, I think twice the guy went to startups that got bought by our company so he became an employee again. He left the first time when his year contract was up, but he's currently an employee now.
He also joined and then left one of our competitors the day before it went public, which must've cost him millions. Unless he was bad with money I'm sure he already had millions.