The UChannel podcast is a compiled feed of lectures at academic institutes all over the world. It is a feed to subscribe to and to pick your favorites from. With an input of more than one lecture per day, I guess there is nobody who listens to them all.
UChannel is an excellent choice to stay updated on hot issues such as the Middle East and Climate Change. On the latter there was a lecture recently by former presidential candidate John Kerry. Kerry speak of what the Americans should do, and have not done thus far, in order to minimize the human impact in climate change and to avert disaster from happening.