Having your lunch money stolen in grade school is bad enough, but having your lunch stolen by an unethical coworker out of the company 'fridge is even worse. If this has happened to you, you'll want to look into the Anti-Theft Lunch Bags. The sandwich bags are printed with convincing renditions of mold on both sides, meaning your coworker would have to be very hungry indeed to pilfer this package.
Ten bucks for 25 bags. And the designer responsible, Sherwood Forlee, also has a couple other tricks up his sleeve.