Openly Licensed Images, Audio and More | Openverse
A search engine for images and audio that’s either under a Creative Commons license or is in the public domain.
CcPublisher 2 - CcWiki
This is a tool for embedding licensing information in files (like MP3s). I'm going to try this out and see how it goes.
Related links
Creating Proprietary Content is Like 'Writing in Sand' | Compiler from Wired.com
Tantek talks about the importance of open media for the longevity of data.