Air Guitar Heroes.

You'll find them in school hallways across the nation--people playing imaginary guitars to songs in their headphones (or just in their heads), contorting their faces like rock stars. Air guitar may seem like a frivolous pastime, but people in Finland take it pretty seriously, as hosts of the annual Air Guitar World Championships.

Performers from all over--no actual musical ability required--come to show off their air shredding skills at the annual event in the city of Oulu. It all started when some Finnish college students suggested--tongue-in-cheek--that air guitar could be the solution to world peace. A nearby festival arranged a local competition, jokingly referring to it as the Air Guitar World Championships. But the event...