My new favorite winter sport! It's like BMX on skis. It's been a favorite at the Winter X Games for extreme action sports — and it's superfast, supercharged and superdangerous. The skiers come out of the gates four at a time, competing for space on the narrow, twisty half-mile course and jockeying for position. They finish in about 50 seconds and get up to speeds of 50 mph, with lots of twists and turns and bumps and jumps along the way. Melissa Block/NPR