New York University's Brennan Center for Justice is doing a study on the usefulness of the "fair use" doctrine when it comes to use of copyrighted materials. They're interested in hearing from artists, producers and others who've been involved in "fair use" issues.

There's a good description of the "fair use" doctrine at the Brennan Center's Freedom of Expression website:
http://www.fepproject.org/fepp/fairuseintro.html

You can take their online survey at:
http://www.fepproject.org/fepp/fairusequest.html