The invention of Silly String was a complete accident that nearly didn't happen. In 1972, inventor Leonard A. Fish and chemist Robert P. Cox set out to create an aerosol spray that would act as an ...

It's messy. It's dangerous. It sticks to your hair. It's silly string, and it's now illegal to possess the pressurized party favor on the streets of Hollywood, at least during Halloween celebrations.

A Silly String prohibition sign in the Hollywood neighborhood of Los Angeles. (David McNew/AFP via Getty Images) To hear police and locals tell it, Halloween in Hollywood two decades ago was out of ...