I always felt uncomfortable about taking anything from the "leave a penny, take a penny" tray in many stores. After all, I never leave any!

Well, one day at a Subway Restaurant, I was one or two cents short, so, instead of breaking a $20 bill, I helped myself from the "leave a penny, take a penny tray."

Boy, was I mistaken. "That's our tip jar!" the cashier said. Needless to say, I stay away from such 'trays' now.