The New York Public Library’s release of 180,000 copyright-free images

All the high-res images are here: http://digitalcollections.nypl.org/

And here's the same kind of thing from the British Library: https://www.flickr.com/photos/britishlibrary/ (try searching "maps")

Some of these collections are really amazing -- These old clothing getups - http://digitalcollections.nypl.org/collections/collection-of...

And the maps, wew, great stuff.