As a teacher more than a techie, I’ve been in a pinch for time and been successful using Wink from DeBug Mode. Upload the swf file through Moodle files and then point to it by “linking to file” under adding a resource. In addition, if you use Audacity to create the audio for Wink, you could strip it off and distribute that alone as an audiocast.

I would be curious if some subjects are more adaptable than others to replacing in-class lectures. To waste class time (which could be used discussion) with content delivery seems ludicrous, yet there is a considerable time investment to create a polished online lecture.