Podcasts are audio recordings which are downloadable on a subscription basis. There is some discussion about whether podcasts are examples of social software, though they can be when embedded in a blog or wiki. In any case, podcasts are a useful Web 2.0 tool.

Podcasts can be used effectively as a source of course content.  Lectures can be podcast.  Outside views can be brought into a course.  Example: Slate.com

Podcasts can also be used as a medium for student work.  It’s not hard to create a podcast.