Tux Radar posts today with mid-length reviews of a half-dozen screencasting programs for Linux: Group test: screencasting apps. They like DemoRecorder the best.
How you know you're not ready for Linux? The post concludes with a suggestion that if none of these meet your needs, you could "roll your own. Almost all GUI apps on Linux are just a wrapper around some powerful command-line scripts. Screencasting tools are no different." :-)
Oddly, there are no links to the reviewed products in the post.