Kalev Leetaru has already uploaded 2.6 million pictures to Flickr, which are searchable thanks to tags that have been automatically added.
The photos and drawings are sourced from more than 600 million library book pages scanned in by the Internet Archive organisation.

 
The Internet Archive is a wonderful resource (The Wayback Machine even more so), but I always felt it was hampered by counter-intuitive search. This is a great stride forward to make historical data more accessible.