Add really funny things to other peoples’ carts and watch them pay for it and see if they notice.
Ask if you can buy a shopping cart.
Constantly wink at a person you don't know. Follow them around and blow kisses to them.
Dart around suspiciously while humming the theme from "Mission: Impossible."
Drag a lounge chair on display over to the magazines and relax.
Drape a blanket around your shoulders and run around saying, "...I'm Batman. Come, Robin--to the Batcave!"
Fill your shopping cart with matchbooks and gasoline and walk around smiling at people.
Gather a bunch of bouncy balls and bounce them into neighboring aisles.
Get 20 people together and play hide-n-go-seek.
Go into the dressing room and yell real loud... “Hey, we’re out of toilet paper in here!”
Go up to the clerk and say code Red! and see what they do.
Go up to someone and start taking items from their basket and put them into yours.
Make a trail of orange juice on the floor, leading to the rest rooms.
Make farting noises as you walk by someone.
Make up nonsense products and ask newly hired employees if there are any in stock, i.e., "Do you have any Shnerples here?"
Ride a display bicycle through the store; claim you're taking it for a "test drive."
Set up a "Valet Parking" sign in front of the store.
Switch the men’s and women’s signs on the doors of the restroom.
Take a snickers bar, go in the bathroom and smoosh the snickers bar in your hand and reach over to the next stall and say "uh do you have some toilet paper over there?"
Walk about 10 centimeters in front of a moving shopping cart and yell "Its gonna get me!"
Walk through the store pushing a cart that is upside-down.
Walk up to complete strangers and say, "Hi! I haven't seen you in so long!..." etc. See if they play along to avoid embarrassment.
When an announcement comes over the loudspeaker, assume the fetal position and scream, "No, no! It's those voices again!"
When someone asks if you need help, begin to cry and ask, "Why won't you people just leave me alone?"
From GetAnnoyed.com