Bob points me to the Internet Archive Audio Archive where there are gobs and gobs of audio files to be downloaded. He warns that the site could cause marital problems, and already I see how that could be possible.
Hear Donald Norman, he of the Psychology of Everyday Things talk about Emotional Design, which was the keynote presentation at the O'Reilly Emerging Technology Conference held in San Diego, California, February 12, 2004.
Or hear Michael Moore speaking at the DNC in Boston in 2004, or How to Meditate, from the Discovering Buddhism Program at the Tse Chen Ling Center, or the Cheshire Public Library (Teen) Podcast, or presidential recordings ... you get the picture.
Oh and here's a tip for listening on an iPod in the car: crank up the volume on any spoken word podcast to 9 or so (doesn't go to 11, sadly) and set the "Equalizer Preset" to "Spoken Word." Makes things a lot easier to hear in a noisy environment.