Weaponized Bacon
A couple coworkers were discussing the claim that the CIA has been covertly eliminating public figures using a "heart attack dart", and that a number of recent high profile "natural" deaths were in fact government assassinations. I countered with the fact that bacon has been known to cause heart attacks, and seemed much more likely to be the culprit than 007 busting in your window with a spy gun.
I was called "close-minded", and one person said something along the lines of: "In the age of 3D printing, where a person can make anything, how can we know what's really going on?"
A few days later, I came in to work with this "Bacon Dart"; claiming it was fired at me by an unknown assailant, and that I may be marked for elimination because our conversation was monitored by the government. Even the staunchest conspiracy theorists among them couldn't help but be amused.