After showing mechanic/artist Walker Canada's Driveshaft Through The Skull Warning Symbol the other day, I was deluged with emails from fellow tech writers expressing admiration for Walker's work and asking to see more. Sadly, I don't have anything quite as twisted as the Driveshaft Skull, but here's a nice Caution symbol (used in a manual to indicate "You're gonna break something if you don't pay attention, schmuck!") that he created.