I enjoy audio books. They are great for listening to in the car, or while you work, or while you're just hacking on something in the evening. They allow me to make maximum use of my busy schedule.
So I'm very pleased my wife just pointed me at http://www.audiobooksforfree.com/ which seems to be a collection of recorded versions of some books that are from Project Gutenburg, and some that aren't, all with small amounts of advertising interspersed throughout the books.
I don't know what the narrators will be like - often that's an important factor with audio books, but I'm definitely going to try it out.