Sometimes, a person accomplishes something so great, so revolutionary, that all they can do is smile as wide as humanly possible and show off the thing. This paper airplane gun, crafted by a 3-D printing and paper airplane enthusiast, is such a device. Wordlessly, the operator fires a series of paper airplanes. Then, with the top of the device removed, he reveals the assembly line inside the weapon. The gun folds the paper and then shoots it out the end -- at a rate of almost one a second.