The most brilliant thing I've seen in quite a while:
Had lunch at Wendy's today. When I was done, I took my tray over to the trash can and was surprised to see two metal rails mounted on the inside. These rails prevented me from throwing the plastic tray out with the rest (which, admittedly, I had a sudden compulsion to try when I noticed the rails). Very simple design, costs little to manufacture, saves the company any number of dollars... Somebody's gonna be a billionaire.
And what makes it so much better is that this had to have been invented by a low-level employee who will never have to empty the trash at a fast food restaurant for the rest of their life.