That’s how to get the ball rolling! The perfect idea doesn’t always spring from your mind fully formed, but “aha” moments abound during prototyping. The inventors of Silly String set out to develop a spray-on cast to help heal broken bones, but in testing different prototypes for the nozzle they tried one that sent the product flying and realized they had the makings of a fun toy. After adjusting the formula, Leonard Fish and Robert Cox pitched the product to toy company Wham-O, which patented the idea and started selling the colorful, foamy spray. The history of Silly String hasn’t been all fun and games, though…in another creative twist, military personnel have used the product to locate trip wires while on patrol.