I too have been asked by readers of this blog if I know of any Mac software that does something similar to ViewletBuilder or Captivate (rumor has it that ViewletBuilder will soon be releasing a Mac version), but I hadn't really found anything. Today I found this list mentioned by Jean-Claude that automatically earned him a place in my aggregator :-)
Several faculty have asked about a product like Camtasia that would work on a Mac. I have nothing to recommend from experience but here is a list. Some of these products just capture an image but several do record video and audio. If you try an evaluation version let me know how it works out. We should be able to integrate with our standard captured lecture system.
[via Drexel CoAS E-Learning]