Last week, I dowloaded and listened to the first episode of The Metamor City Podcast. I liked it so much that I've subscribed, and am going back to download the older episodes that I missed. I can't recommend it enough.
Metamor City is a fictional world created by Chris Lester, and the podcast consists of audio fiction based in that world. Chris combines short stories and novel-length pieces, and gets the big names in podcasting to help him dramatize the stories. So far (after only the first story "Welcome to the City"), I am hooked. This is excellent, high-quality stuff. The writing is great, the production quality is top-notch, and the world is really, really interesting -- I can't wait to find out what all he is going to do with it! The next story (Episode 2) is called "Huntress" and I'll be listening to that on the bike tomorrow morning.
Check it out if you can.