TechSmith, makers of Morae and Snagit, have released a Mac version of Camtasia, the screencast video recording software. The software allows you to capture the screen, audio and iSight input, and provides simple drag and drop editing including a lot of built-in transitions and effects. You can then easily export the HTML and SWF for embedding in a web page.
Looks like an easy to use alternative that might take the work out of producing screencasts. The video suggests that TechSmith have really thought about the primary demo and training use cases.