Finding or Publishing?
If you are looking for content that you can utilise in channels, or if you want to ensure that content you are publishing is clearly secured against inproper use then Creative Commons could be for you.
http://creativecommons.org/Creative Commons licenses provide a flexible range of protections and freedoms for authors, artists, and educators. We have built upon the "all rights reserved" concept of traditional copyright to offer a voluntary "some rights reserved" approach." CC is a nonprofit organization.
All of thetools are free.
There are other places where Creative Commons conent can be found.
Try:
http://search.yahoo.com/cchttp://www.flickr.com/creativecommons/