Prez tool
ProfCast stands out as a nice audio-visual presentation tool that’s especially geared towards those Mac users who just can’t do without their Keynote. It’s very easy to produce (just drag, drop and record). As I see it, one of its best strengths is compression; it does a nice job of keeping the file size manageable. You can also export it in a wide variety of formats (e.g., .mov, .mpeg). You can also upload it to iTunes and configure it for RSS.
You can try it out free for 15 days and then after that it’ll run you $29.95 with the qualified educator’s discount and $59.95 for the regular price; although I think even the $59.95 price tag is more than reasonable if you plan to produce a fairly regular series of presentations for your students.