Google has added a Creative Commons filtering capability to its Image Search results, enabling users to query for images specifically labeled for "reuse," "commercial reuse," "reuse with modification" or "commercial reuse with modification."
Ideally, the feature shall enable a broader array of commercially-usable images to users that don't want to pay a stock photo company for imagery, and don't want to deal with the copyright headaches associated with "stealing" an unlicensed picture from Image Search.
The option isn't currently available on the user interface, but you can enable the filter by adding a certain parameter to your search URL (in this case, just replace "mountains" with whatever you are actually searching for):
- For public domain images — http://images.google.com/images?q=mountains&as_rights=cc_publicdomain
- For images licensed with Creative Commons Attribution (that is, images you can use as long as you attribute the image back to the creator) — http://images.google.com/images?q=mountains&as_rights=cc_attribute
- For images licensed using Creative Commons Attribution Share-Alike — http://images.google.com/images?q=mountains&as_rights=cc_sharealike
In May, Yahoo added a Creative Commons license filter to its own Image Search. Other services, such as compfight.com, enable users to seek Creative Commons-licensed work on flickr.