Yahoo now has an audio search. It provides a separate result pages for music podcasts and other. Missing MP3 tags make the results less useful.Since I picked on OCLC just now, I should mention they do have a good collection of talks available, their Distinguished Seminar Series. I've downloaded several of these, added some tags and moved them to my player. Without titles, artists, genre, or year they would not copy.Over on Research Buzz, there is the posting Setting up Auto-Discovery of Podcasts By Keyword. Looks useful, it takes a few tools to do this, but all are free and the instructions clear.