http://www.the-athenaeum.org/

More art than you ever need. Not really. But there is quite a lot of art here. What so fun about this site? Besides collections of work from artist you have never heard of, there is a game! It's called the "Artwork Faceoff!"

http://www.the-athenaeum.org/art/faceoff.php

hours of fun...well at least 20-30 minutes of fun.