Last week Google added a creative commons drop down filter to Google Image Search. The filter looks like this:
This feature allows you to restrict your Image Search results to images that have been tagged with licenses like Creative Commons, making it easier to discover images from across the web that you can share, use and even modify. Your search will also include works that have been tagged with other licenses, like GNU Free Documentation license, or are in the public domain.
This feature also helps artists who want their images to be discovered and reused across the web — on their own terms. Creative Commons licenses allow artists to specify the ways others may use their work. Artists can license their images for general reuse, or for noncommercial reuse only. They can also decide whether or not to grant people the right to modify or remix their images. Once they've chosen to make their work available online under these terms, Google Images helps people start to find and use it.
Yahoo has had this feature since May or so.
Yes, this is a help to both content owners and searchers, now if only more people understood what creative commons was.
Forum discussion at WebmasterWorld.