Hey there,
I made up a litte POD comic book of photos of the skull for reference (Yay ComiXpress!). It is mostly specific to comic book, fantasy and tattoo artists or maybe just unusually strange people like me, but here are most of the pages...
http://smg.photobucket.com/albums/v156/baileyaya/

I've been using them quite a bit for paintings. Some other forums seem to find them useful so I figured...comic books...
(edited, hope that cleared it up, thanks for the heads up =)






Thanks for checking them out if you get the chance =)

...lolwut?