I recently got a copy of Camtasia and have been producing screencasts with it and now two of them are available on Google Developer's Channel on YouTube. Camtasia is really easy to use and comes with a nice set of screencasts that explain how to use it. You would hope that would be true for software for producing screencasts. The autozoom feature is nice, but setting up keyframes is so easy I don't really mind when it gets the proportions wrong. It's worked out well enough that Lynne has now bought herself her own copy to produce screencasts for her business.