WhereToFindThingsToRemix

• Creative Commons Search Page
• Electrobel Community More than 10.000 electronic music songs released under CC license.
• BeatPick A creative commons music licensing site
• CCMixter - A Creative Commons Remix community site.
• Common Content - Lots of stuff
• Magnatune - CC music (classical, new age, etc.)
• Jamendo - An archive of music albums under Creative Commons licenses
• Open Clip Art Library
• everystockphoto.com - Search engine and member bookmarking for Creative Commons Photos
• The Internet Archive - Project dedicated to maintaining an archive of multimedia resources, among which Creative Commons-licensed content
• Ourmedia - Media archive supported by the Internet Archive
• Creative Commons Search from Yahoo!
• Open Source Web Design Web Templates

This list is based on a list from http://en.wikipedia.org/wiki/Creative_Commons and improved slightly.