NYPL Digital Gallery Open to Public
mountiealpha writes "The New York Public Library has digitized over 275,000 images from their colletions, and made them freely available available online. The 'NYPL Digital Gallery provides access to over 275,000 images digitized from primary sources and printed rarities in the collections of The New York Public Library, including illuminated manuscripts, historical maps, vintage posters, rare prints and photographs, illustrated books, printed ephemera, and more.'" Update: 03/04 17:30 GMT by Z : They're updating the site to handle high traffic volumes, but there is an informational page available with details on the site.
Seems that Libraries have to follow certain guidlines in order to make these electronic reproductions.
e .php
Copyright Issues for Libraries When Digitizing Materials for the Web
When digitizing documents or other objects to be made available on the World Wide Web, a library first needs to determine whether the item is protected by copyright or whether it is in the public domain. If the material is protected by copyright, the library will need to obtain permission from the copyright owner before making the digitized copy available through the World Wide Web. If the item is in the public domain, the library does not need permission to digitize it and make it available.
more here:
http://www.mlcnet.org/services/copydigitiz