Firefox extension (add-on)

http://add-art.org/

Replaces ads with art. (Disclaimer: I have not yet tried it. Will now.)

pem - dutch paintings

Hi res images:
http://pem.org/press/press_release/174-dutch_flemish_masterpieces_unveiled_at_pem#publicity_images
and look at the "publicity images" item in the right margin space. A large download.