In almost any city you visit around the world, at some point you'll see somebody's shoes tossed over a power line, a high tree branch, or some other difficult-to-reach spot. Why do people do it?

This terrific Australian short documentary from Closer Productions, The Mystery of Flying Kicks, does a great job exploring the dizzying number of answers to this question. The filmmakers got answers from people all over the world, describing local legends and customs around tossing shoes into the air.

One of the pervasive myths, which Snopes has debunked, is that the shoes are used to mark the locations of drug dens or gangs. It appears that people toss their shoes — or other people's shoes — for all kinds of reasons. Sometimes it's celebratory, to mark a rite of passage like finishing up basic training in the military (painting your boots and tossing them festively over high wires is a military tradition in the US) or losing your virginity. Some say it's a form of bullying, while others say it's art or political protest.

The urge to launch your shoes into the air, hoping they'll dangle there forever, seems to be almost universal. And like many human practices, it's taken on new meanings the more it has spread.