OK, I've finally discovered some podcasts actually worth listening to!
First and foremost, let me recommend the Bored-Again Christian. This podcast is a 20-30 minute introduction to "post-contemporary, post-conservative, post-modern" music from Christian artists - unknown, lesser-known or otherwise ignored by the larger "CCM" community. Check it out. You'll be glad you did!
From that podcast, I have discovered Sufjan Stevens - a tremendous breath of fresh air! I downloaded his Illinois from iTunes and have enjoyed each of the 24 tracks I've listened to so far.