C: Creative Commons
More about Creative Commons
If you are looking for free resources, here are a few places to find work (images, video, audio, and other media) released under a Creative Commons license:
Not a search engine in itself, but by searching from this page you can access search services of other organizations – Google, Yahoo, Flick, blip.tv, jamendo, SpinXpress, and Wikimedia Commons. You can specify whether you want to use the work commercially and/or if you want to modify the work, but you cannot search by specific license.
The Commons hosts images, sound, and video that are either licensed with a CC or GFDL license. Many files are even in the public domain. You can search by topic but not license.
This is a place to find a list of more groups and organizations that provide CC-related services. Audio, image, video, and text.