PUBLIC MARKS with tags hs:dd & "search engine"

As of February 2006, the Wikimedia Commons, a central media archive operated by the Wikimedia Foundation, contains about 450,000* files uploaded by nearly 30,000 registered users. Each of these files is available under a free content license or in the public domain; there are no restrictions of use beyond those relating to use of official insignia. Licenses which limit commercial use are considered non-free

Yotophoto is the first internet search engine for finding free-to-use photographs and images. you can even search by color scheme. Now indexing well over a quarter million Creative Commons, Public Domain, GNU FDL, and various other 'copyleft' images.