Jeff Curto is a professor at a community college outside of Chicago. He has 2 podcasts dealing with photography that I'm sure some here will find very interesting.
One is call Jeff Curtos's Camera Position. These podcasts are pretty short (less than 10 minutes) and he discuses things geared toward fine art photography, and composition. It's interesting and informative no matter what type of gear you shoot with or what type of photography you're interested in.
Jeff's other podcast is called Photo History, and is much longer (1.5 - 3 hours). I have just started this podcast so I can't really tell you much about it yet, other than it is his lectures from the Photo History class that he teaches.