Carry around the "Get out of jail free" cards from Monopoly just incase you ever get arrested.
carry around pocket sand incase you want to go to the beach but live too far away
if you want to hit on a girl but arent sure if she likes you, just whip out your dick. if she starts sucking it, she likes you, if she screams and runs away, she probably doesn't like you, but now you can find out without having to ask!