Screencasting – What is the ideal length?

What I’ve learned over the past few years is that it is much harder to make a shorter screencast than a longer one. For the blog, my goal is usually around a 3-5 minute video. And, if I’m really pushing it, 10 minutes max. The shorter the screencast, the more I need to prepare. I know I personally prefer shorter videos that I can ‘digest’ quickly. And, if the screencast is longer, it needs to be really engaging. Otherwise, I prefer the screencast broken up into small chunks.

I asked on Twitter to see what people thought the ideal length of a screencast was. You can see some responses to below. One of TechSmith’s Flash Developers, Brooks Andrus, has an interesting post on his blog proposing 120 seconds for video length. Is that long enough? I’m really curious to hear what you think. What’s the ideal length of a screencast or Jingcast? How long are you willing to watch? Other thoughts?