I happened on a very nice demonstration of the beauty of OPML directories:
Click here for a succinct, live directory that traverses the entire history of podcasting, from the first experiment with enclosures, through Chris Lydon’s political coverage of the Democratic Presidential Primary, to the first Morning Coffee notes, to Dave Winer’s most recent Coffee notes.
These audio files portray a fascinating slice of history, immediately accessible.
The directory is displayed in search results at http://OPMLsearch.com and is accessed–if you lose the pointer above, by a search on OPMLsearch for “http://www.morningcoffeenotes.com/rss.xml”and selecting the first item (click here to run the search for yourself).