A substantial list of original, modern fiction, mostly self-published and read by the authors or their friends, and often quite well-read or even dramatized with a full cast and sound effects. The literary quality of these works varies; some entries are very well written, others less so, but it's easy to explore and find what you like. Subscribe to podcasts or download existing works broken into short podcast-sized chunks.
A large collection of poetry by published and classic poets, in audio format, sometimes read in the author's own voice.
Public Radio Podcasts
Podcasts from NPR including the TED Radio Hour, news, science, interviews, arts, and more.
Intended for adults, podcasts collected from everywhere, by iPodder, the website which lists "hand-picked, peer-reviewed podcasts that you can count on for quality information and entertainment."
Thoughtful audio books ranging from Lewis Carroll and H.G. Wells to Saki, Gandhi, and Nietsche.