Center for the Study of Innovative Freedom
http://c4sif.org/
http://c4sif.org/resources/

IP-Policy: A Comprehensive, Dynamically Updated List [wiki] of Anti- and Pro-Intellectual Property Materials
http://ip-policy.wikispaces.com/

Molinari Institute—Anti-Copyright Resources
http://praxeology.net/anticopyright.htm

Against Intellectual Property by N. Stephan Kinsella, Esq.
http://mises.org/books/against.pdf (.pdf, 70 pages, 342 KB)
http://www.stephankinsella.com/publications/#againstip

Against Monopoly: defending the right to innovate [blog]
http://againstmonopoly.org/

Against Intellectual Monopoly [online book]
http://dklevine.com/general/intellectual/againstfinal.htm

The Public Domain: Enclosing the Commons of the Mind
http://www.thepublicdomain.org/

Question Copyright
http://questioncopyright.org/