I downloaded Fear and Loathing in Las Vegas. I'm glad it was free. The narrator reads it fairly flat, like recounting the events of a warm summer's day, and transfers none of the urgency and weirdness of the book. I can't say I recommend downloading this one at all.
"This American Life" show is an hour-long radio show broadcast on NPR station and it's a terrific, ecletic, interesting program. That said, I can never seem to catch it when it's broadcast and since there's no TiVo for radio, I often miss out on episodes. I've wanted to pick up an audible.com subscription for several years, but have been put off by the price. Now I've got a month's worth (four shows!) to listen to for free.