Stephen Downes

From the website: "CommonsDB Explorer helps you discover declarations about Public Domain and openly licensed works. These declarations are provided by trusted repositories of cultural, scientific, and creative materials, including the Europeana Foundation and Wikimedia Commons. By bringing together rights information from these sources, CommonsDB makes it easier to confidently reuse, share, and build on openly available content." I'm not sure I would ever have the time to use it to declare my 40,000 images, but for institutions with the resources, it offers a good way to document the status of their resources.