I explored Yahoo!Podcasts and Podcast Alley. The Yahoo one was good for finding popular and news podcasts. When I did a search for library ones, I didn't have much success for ones I'd want to listen to. So I signed up for the Royalty Report about the British royal family. The presentation of the podcast speaker wasn't very good, but she had some good tidbits of royal news.
The Podcastalley.com one was good for finding lots of library-related podcasts. I signed up via my Bloglines account for Library Geeks (I listened to the podcaster interview web search guru Gary Price), Open Stacks, and LibVibe (this one wouldn't open because it needed QuickTime to run).
I had never listened to a podcast before; of course it sounds just like a radio show --but I learned people can "call-in" to a live show to ask questions and chat, which is very interesting given that someone with the necessary technology can be anywhere in the world and participate in a show.