An unusual drawing of a skull that I thought you might enjoy. It comes from artsconnected.org, a newly completed website that searches the Minneapolis Institute of Arts and the Walker Arts Center collections. From their website :
Explore the combined collections of the Minneapolis Institute of Arts and the Walker Art Center through hundreds of new features in ArtsConnectEd. Search over 100,000 resources in the Art Finder, including works of art, texts, audio, video, and interactive resources. Save and customize items in the redesigned Art Collector. Comment, tag and rate everything!