Do you find developer screencasts useful?
praptak: No navigation, no copy/paste, fixed speed, hard to do in parallel with actually monkeying with the product (the best way to learn anything :) ).They might have a niche for things that are heavily GUI-oriented. Click there, drag this from here to there, slide this slider - this is where I think screencasts might be both faster and clearer than narration + screenshots. But that's rather user- than developer-oriented.