Information on the use of digital and photographic reproductions from the Smithsonian collections.
Creative Commons is a nonprofit organization that develops, supports, and stewards legal and technical infrastructure that maximizes digital creativity, sharing, and innovation.
Many Flickr users have chosen to offer their work under a Creative Commons license, and you can browse or search through content under each type of license.
a database of over 40 million freely usable media files to which anyone can contribute
ARTstor partners with several institutions to make digital images freely available for use in academic publications and elsewhere. More information is available on ARTstor's collaboration page.