Xtreme Skateboarding: Time Machine IV

From its first appearance in the 1950s to its modern incarnation as an extreme sport, skateboarding has had its share of ups and downs -- figuratively and literally. Featuring jaw-dropping moves on the Pipe Grande and a behind-the-scenes peek at the making of Tony Hawk's Pro Skater video game, this edition of the series chronicles skateboarding at its best. The top vertical and street skaters are on hand to deliver loads of intense action.