This is an engaging, to-the-point podcast with excellent interviews with independent film directors in every medium from traditional and cg animation to documentary and feature films. The 40-odd episodes, some nearly an hour in length comprise an excellent film school on an i-pod.
(available in flash, mp3 and on iTunes)
LensWork Magazine Podcast
Miette's Bedtime Story Podcast
Excellent reading voice, most stories about 45min, check out the hundreds(?) of archived stories for short stories by Dostoevsky, O'Conner, Calvino, Mann, Greene, etc.
School of Visual Arts Lectures
Videos of lectures on graphic design given by famous designers like Milton Glaser, unfortunately they are video only, so they don't work on old mp3 players.
Mars Hill Audio Audition
"...living as disciples of Christ pertains not just to prayer, evangelism, and Bible study, but also our enjoyment of literature and music, our use of tools and machines, our eating and drinking, our views on government and economics, and so on." Mars Hill Audio is a quarterly audio journal, which I've enjoyed for years, this is there new (free) podcast.