Having previously discussed the potential for crochet-hook mayhem, I feel I've lost any right I might have had to mockery when confronted with playing cards as weapons. The book itself (quite properly called Cards As Weapons, by Ricky Jay) is, sadly, very, very out-of-print.

Tongue in cheek or no, there's still a decent little distraction to be got from a quick playing card in the eye. Or from nude photos, I suppose.