The Astronomical Society of the Pacific -- a non-profit educational group that does great work in getting the word out about astronomy -- has just released a dozen free audio recordings of lectures from well-known astronomers. They include SETI scientists Frank Drake and Jill Tarter, planet finder Geoff Marcy, supernova guy Alex Filippenko, and many others.
I recommend taking a listen to at least Alex's talk. He is a great speaker, and beloved at Berkeley where he teaches. I've known Alex for many years, and he's a nice guy, and his talks are always very cool. He is on one of the teams that discovered dark energy, the bizarro force behind the accelerating expansion of the universe.
But you also get talks from other top-notch astronomers about Venus, Mars, and even little maligned Pluto. If you have a long drive ahead of you, or lots of gardening, or just want to laze in the Sun and learn a bit more about the cosmos, then go and grab these free downloads.
Also, free bonus: ABC Australia just uploaded a transcript of an old interview with physicist Richard Feynman, one of my heroes and an amazing man. His ability to talk about the beauty and methods of science was pretty much unparalleled.
Tip o' the white lab coat to Larry Klaes for that last bit.