My find for this week isn't a book, but rather a book site. LibriVox.org is a site that provides free audio versions of books in the public domain (no longer protected under copyright). Their tagline is "acoustical liberation of books in the public domain" and all of their recordings are done by volunteers. They've been going strong since August 2005.
I'd heard about LibriVox before, but I hadn't actually checked out the site before this week. I visited it early this week, poked around a bit, and downloaded the first book (28 chapters) of War and Peace (available here). I'm on chapter 13 right now and I'm happy as a clam. The recordings are all really good quality and while the reader sometimes changes from chapter to chapter it hasn't bothered me at all.
I'd encourage all of you to check out LibriVox.org. Good stuff there.