Just as there are blogs on almost every interest, there are also podcasts on many different interests from entertainment to sports to shopping. I looked for some library-related podcasts on Podcast Alley, which I liked better than Podcast.net.
I have listened to podcasts before... one was of a radio program that I couldn't listen because I was never home or in my car at the time. Another one I have enjoyed was one called Acorns and Merlot. It was started in 2005 by two high school kids from the suburbs of Pittsburgh. I don't listen to podcasts on a regular basis, this is something I have done when I have had the time or when I remembered to listen.
A good idea for the library would be to have storytelling podcasts for children! A library I used to work for had 'storytelling' over the phone, and this was a very popular service provided to the juvenile patrons. Podcasts may also be good for booktalks for all patrons, not just children.