Some days back I noticed a link at The Boar's Head to some sermon audio of Reinhold Niebuhr.  The couple I've listened to are very interesting.  I do not agree with Niebuhr on all things, but I certainly think he is worth hearing.  His was a very important voice in American theology, and, to some extent, still is. 

Again, very interesting.  Check it out.

(I had to download RealPlayer to be able to play these, though maybe some other player can do so as well.)