Copyright-free fine art

Anything worse than an art teacher trying to source copyright-free artwork? Thought not.
Well our good friends at Wiki with a little help from The Yorck Project have come up with a 10000 image gallery of high-resolution .jpgs of largely European paintings which, on a brief acquaintance, covers everything from Breughel to Whistler & beyond. All are copyright The Yorck Project but are in the public domain worldwide & licensed under the GNU Free Documentation License.
The gallery can be found here.