Astronomy Cast -- They have a pretty big show archive that has aged very well. In Our Time, a BBC radio podcast focusing on history. PBS Frontline (a tv show,

Astronomy Cast -- They have a pretty big show archive that has aged very well. In Our Time, a BBC radio podcast focusing on history. PBS Frontline (a tv show, not a podcast) streams all their shows online. Great for current events. The Economist Audio Edition requires subscription to magazine, but if you want to catch up on the entire world in a couple of hours, this is the way to go.