Jon Udell, who basically created the genre of screencasts, once wrote:
Now that it's almost trivial to make and publish short screencasts, can we expose our software-tool-using behavior to one another in ways that provoke imitation, lead to mastery, and spur innovation? It's such a crazy idea that it just might work.
Emphasis added because I just experienced the opposite effect. After watching a screencast demonstrating SLIME, or Superior Lisp Interaction Mode for Emacs, I have a much clearer idea of how much I want to use this technology: not at all.
Granted, I skimmed a lot of the fifty-five minute video on creating a morse code translator (and they say Lisp isn't useful). But when the narrator says, fifty minutes in, "this example is so simple that I can just look at it, and I know exactly what is going on," I think it comes very close to a perfect definition of irony. And then at the end, when he tries to quit and everything goes haywire, it's just pure comedy. I laughed, I cried (almost), but I did not develop any desire whatsoever to imitate what I was watching. Much the opposite.
UPDATE: Please read this post before commenting here. I didn't post myself on Planet Lisp, and I disclaim any implied understanding of or caring about Lisp that goes with showing up there.