The screencast is meant to be an introduction to OPML (what it is) and then goes into a number of different uses and applications (what it can do - not exhaustive by any means), but hopefully something there for you too if you are already familiar with OPML.
Plenty of references to RSS, so if you don't know what RSS is then see this RSS 101 screencast.
Resources I reference in the OPML 101 screencast include the following:
- opmlmanager.com, my OPML outliner, and my OPML file
- Dave Winer's OPML Community Directory and OMPL site, and the Seattle Mind Camp OPML file I created that Dave uses to render out his Seattle Mind Camp Roll.
Hope you find this useful. Happy OPMLing!