The New York Public Library has released more than 20,000 high resolution cartographic works (maps!) for free, to view and download. "We believe these maps have no known US copyright restrictions." All can be viewed through the New York Public Library’s Digital Collections page and downloaded through their Map Warper. (Via) [more inside]
The Cleveland Memory Project is an archive of photos, postcards, videos, recordings, clippings, ebooks, personal papers, maps and other historical "goodies" about the city. "It's a collaborative endeavor of many local historical societies, public libraries and government agencies who have mounted their own local history." On Flickr. [more inside]
New York Public Library is crowdsourcing the rectification of maps in their digital gallery. Help match rare maps of NYC to more precise current maps, browse rectified maps, or lend a hand rectifying maps of Haiti to help relief efforts.
The U.S. Naval Observatory Library features high-res scans of images from antique books dealing with astronomy and navigation. Wallpapers, ahoy!