I'd need to go shoot it, but what about the back LCD of a camera with the "no Card Found" message? Or the "no images" one when you try to chimp with an empty card?
update with processed shots from quick trial shoot, a couple candidates:
back display http://www.smugmug.com/photos/1213860545_DJoeg-M.jpg
top display closeup http://www.smugmug.com/photos/1213860627_Y8PWQ-M.jpg
I shot it all with a solid white background so the image could just feather into the the background on the 404 page without a border any anything.
and a sneak peak behind the scenes: back stage http://www.smugmug.com/photos/1213874305_g8igY-S.jpg back stage http://www.smugmug.com/photos/1213867900_5cNJ9-S-1.jpg