I am a religious user of podcasts, even though I feel that many of the modes of transmitting them are outdated. I have an iphone and can get many podcasts that way, although its not easily browseable. On my iphone I've listened to The Meditation Podcast, as well as the Rachel Maddow show in podcast format, among others. I listen to NPR while I am doing the money at work. My favorite shows are To The Best of Our Knowledge, This American Life and Radiolab. TTBOOK uses windows media player (and always crashes my browser), This American Life uses .mp3s that you download (they used to stream, but I think it was costing too much money), and Radiolab has a player embedded on its site.
As far as library podcasts, I did not dig the voice of the guy doing LisNews (it grates on my nerves, and he sounds full of himself). NTRLS has done some useful podcasts with Nell and others asking questions, but the sound production isn't great and sometimes the podcasts get too talky. I guess that is why my all time favorite is Radiolab because its a sound experience reaching into my brain and pulling out wonder and excitement. And their subjects can be pretty boring. We've been thinking about putting a couple of stories up on our website done by the children's librarians, but I think we should focus on getting our website out of the year 2000.
My new favorite is Stuff You Should Know by howstuffworks.com. Chuck and Josh have a good rapport and it is like listening to someone having a conversation with another person. They make even toxoplasma sound like something I should know about.