Advanced Search on Flickr - scroll down for Creative Commons options! There are over 100 million Creative-Commons-licensed photos on Flickr.
There are few big collections of Creative Commons licensed videos, but you can find some on YouTube, Vimeo, and BlipTV with some smart searching (hint: try putting the words "creative commons", in quotes, with your search terms). The Al Jazeera news agency has one of the larger collections of high-quality Creative Commons licensed video around right now.
Creative Commons is both an organization, and a movement in response to expansive copyright protection. Using Creative Commons Licenses, artists and creators can make their work proactively available for public use, under specific conditions. With Creative Commons works, you may already have permission to use them!
Creative Commons is not "anti-copyright", or even an alternative to copyright - it's just an option of a different way to share works, and it fundamentally relies on copyright - you must own a copyright in a work in order to make it available under a Creative Commons license.
Creators Control Sharing
Creative Commons Licenses allow creators to make their works available for use - and they allow creators to put conditions on those uses. U.S. Copyright law does not usually care much about attribution or correct citation (citing a source correctly will not save you from infringement, nor does not citing make a legal use presumptively illegal) - but with a Creative Commons License, creators receive attribution as a condition of almost all of the licenses. Creators can also restrict use to noncommercial circumstances, authorize only identical copying with no changes, or require users to also make their derivative works available under a Creative Commons License.
One great advantage of Creative Commons licenses for creators is that they can cut down on administrative overhead for frequent approved uses of your materials. The copyright sections of this website, for example, are already available for non-commercial re-use (with attribution) - so if another University would like to use this material on their website, they don't even have to ask!
Users Get Certainty
Even in the best of circumstances, it can be difficult to be sure that a given use is acceptable under fair use or other formal copyright exemptions or limitations. Creative Commons licenses give much more certainty to your uses - if you meet the conditions of the license, your use is pre-approved!
Most of the illustrations on this website are used under a Creative Commons Attribution-NonCommercial (or by-nc) license - we don't even have to consider the fair use factors - we just know our use is okay.
Detailed Information...about the suite of mix-and-match Creative Commons licenses
...FAQ for people thinking about using a Creative Commons license on their own works
...FAQ for users of Creative Commons-licensed works
...tools for finding Creative Commons content
This web site presents information about copyright law. The University Libraries make every effort to assure the accuracy of this information but do not offer it as counsel or legal advice. Consult an attorney for advice concerning your specific situation.