I came across a great piece of software called ProfCast that lets you turn a Keynote presentation into an enhanced podcast. These podcasts are very small as it is jut an audio file, but when viewed on an iPod or within iTunes, the artwork changes for the slide. It's a pretty cool way for teachers to share their lessons, and the whole process is very easy for the mildly tech-savvy to perform. I covered how to do this very task using iWork and Garageband in the new iWork book, but this application saves several steps and is very pleasant to use. You can create a podcast directly, sent it to GarageBand or iWeb, or take it directly online to a user-specified server (.xml authoring for the feed is included). At $25 its an affordable tool all Mac-based educators or technical trainers should add.
UPDATE – The new version also works with PowerPoint