Have you ever looked at a PCB and burst out laughing?
Have you ever looked at a PCB and said "Wow, that is amazing"?
Have you ever seen a PCB that artistically expressed criticism of society's treatment of the poor?
I'm focusing here on the PCB itself as art -- rather than, say, some large artistic installation that may have light, sound, motion activated by some PCB.
(I hope a question focusing on artistic style rather than functionality isn't completely off-topic for chiphacker. I was inspired to post this question after seeing the amazing artwork that endolith mentioned in the Chiphacker "Best licenses for Open Hardware" question ... and seeing The Best CD case insert... ever. )
EDIT: Wow, that's a lot of amazing artwork. I wish I could give everyone a prize for telling me about each piece of strange and wonderful artwork.