Say, "Hmmm, I've never seen that color before."
Drop a marble and say, "oh shoot!! My glass eye!!"
Using a small squeeze tube, spread peanut butter on a wad of toilet paper and drop it under the stall wall of your neighbor. Then say, "Whoops, could you kick that back over here, please?"
Drop a D-cup bra on the floor under the stall wall and sing "Born Free"
When you're in a bathroom stall take a milk chocolate candy bar with you and when someone is next to you, squish it in your hand and reach under the stall wall and say "You got any more toilet paper over there, This side's completely out."