Try out the free audio books on LibriVox. You can listen to them on your computer, iPod, or MP3 player.
“LibriVox volunteers record chapters of books in the public domain and release the audio files back onto the net. Our goal is to make all public domain books available as free audio books.”
I just downloaded the Anti-Federalist and the Federalist Papers to iTunes and plan to listen to them when I get a chance. These are works I’ve been meaning to read forever. I’ll try to listen to them instead. I searched the catalog a bit and discovered audio works of Descartes, Plato, Martin Luther, Augustine, Aquinas, among others.