Self-proclaimed hacker and mischief-maker Kevin Mitnick's business card doubles as a break-out lock picking kit. The card has a set of fully functioning lock picking tools that you can immediately pop out and start using. How clever is that!
Headhunter - Completely edible for 100% discreet disposal with 'read then eat it' instruction.
As hair-grip holders from a hair and and make-up artist
Circumcizer ... OUCH!