I have just recently started to make my way through Arizona State University's Darwinfest podcasts, starting with E.O. Wilson's fine lecture on "Darwin and the Future of Biology." Wilson is a fine speaker: slow measured cadence, with an unexpected Southern drawl, and clear love of his subject. He kept me rapt, easily, for the full 53 minutes.
On a tangent, the MP3-player, coupled with podcasting, is a wonderful invention, so able to insert productivity into normally barren stretches of time. To be sure, like cellphones and computers, it can be a double-edged sword—you can fill it with time-wasting nonsense, and one must at times turn it all off, anyway, to ensure at least a few silent spaces for reflection—but, if one knows how to use it properly, I would say it is a radically life-enhancing piece of technology.