Sometimes assholes rush to beat you to the lines in stores here are some things to do to embarrass them or just piss them off:
Put alot of condums in there cart towards the bottom.
Hide magasines in there cart so that they dont know what there buying and wonder why they spent so much.
If its a girl stick expensive earings or something small in her purse so that the alarm goes off on them as they leave.
Walk away and throw gum in there hair.
Ask them why they are hiding something in there pocket so clerk notices.
Yell he or shes got a gun and run away so that they dont know it was you.
Bump there shoping cart forward reapetedly until there get pissed off and start yelling.
Stare at them until they notice you and eventually get mad.
whistle until they get agrivated and start yelling.
Act like you hav trets and reapetedly yell at them.
Just run after him in the parking lot and run into his cart causing him or her to hit someones car.
Bump into his or her heels as they start to walk away.
Drop vagisil and ask them if they have an itchy problem and if they need anly help with it.