This looks very promising. Podcasting presentations
ProfCast lets you record and publish your Keynote and PowerPoint presentations
(Via Mac Gems Weblog.)
From the ProfCast website:
ProfCast is a versatile, powerful, yet very simple to use tool for recording lectures including PowerPoint and/or Keynote slides for creating enhanced podcasts. ProfCast provides a low cost solution for recording and distributing lectures, special events, and presentations as podcasts. ProfCast offers an integrated workflow that makes creating, recording, and publishing podcasts easy. It’s as simple as Launch, Load, and Lecture!