The Boston Public Library has put 15,827 photos into Flickr, using the least restrictive Creative Commons licenses possible. Tom Blake, the Digital Projects Manager at the BPL reports “he images on our Flickr account have been viewed collectively over 1.6 million times since we launched the account in March of 2008.”
The photos I dipped into were well marked up with metadata, and tagged. (Their new collection is called “Misc.” :) Some great stuff there. E.g., if you’re interested in the early Red Sox, try these. Or stereopticon images.