Library of Congress + Flickr = tagging for everyone
Most of us, I think, would agree that democratization of information is a good thing. Making books, art, music freely available to more people can only bring about societal enrichment. The New York Public Library has a history of doing just that.
Working with the idea of social collective knowledge, libraries seem to be pushing the boundaries further. Even the Library of Congress is considering the benefits of allowing patrons to manipulate and create content. Recently the LOC collaborated with Flickr, uploading two collections of photographs with no applicable copyright restrictions, and allowing other Flickr users to tag the photos with their own descriptions. It is an interesting idea and many of the photographs are great, especially the color transparencies.