Larry Lessig’s book “The Future of Ideas” is now free to download under Creative Commons attribution-non-commercial license.
Published in 2001 by Random House, the book addresses IP and the impact on it of the internet. You can read an excerpt here.
Lessig’s other books are also available free under a Creative Commons license:
Free Culture: How Big Media Uses Technology and the Law to Lock Down Creativity (Penguin Press, 2004).
Code And Other Laws of Cyberspace, Version 2.0 (Basic Books, 2006).