The US National Archives has a project underway that some may be interested in:
Native American Photographs Tagging Mission
Citizen Archivists, we have a new mission for you! More than 18,000 photographs from the Records of the Bureau of Indian Affairs (BIA) are now available in the National Archives Catalog. We are looking for Citizen Archivists to add specific topical subject tags to each photograph in the Record Group.
Thanks Al Adams and Mary Richardson for bringing this to our attention.