I was trying to get a piston out of a Ford 460 once, and it wouldn't budge. So with my hand on the top of it like a spider, I used the closest screwdriver, a long, skinny straight one, to pry under the top ring. Of course it slipped, and went right into the webbing between the index, and second finger. I pulled it out really quickly, so I'm not sure how far it went in until a bone stopped it, but it was WAY too far.
When I was building my first stock car, I was cutting some interior sheet metal out with a cutoff disc on a 4 1/2" grinder. Near the end of the cut, the disc caught something and shattered. The last little piece of metal broke off, and shot straight into my left bicep, like a knife. Left a nice scar.