Cultural tidbit: Parkour is translated to Chinese as “Pao Ku” (跑酷 － literally, “running cool.”)
For those unfamiliar with this dangerous yet nifty youth/urban trend, here’s an edited version of the Wikipedia take (I have tried to make it more broadly understandable):
Parkour is a physical activity that is difficult to categorize. It has no set of rules, team work, formal hierarchy, or competitiveness. It most resembles self-defense of martial arts.
According to David Belle, “the physical aspect of parkour is getting over all the obstacles in your path as you would in an emergency. You want to move in such a way, with any movement, as to help you gain the most ground on someone or something, whether escaping from it or chasing toward it.” Thus, when faced with a hostile confrontation with a person, one will be able to speak, fight, or flee. As martial arts are a form of training for the fight, parkour is a form of training for the flight. Because of its unique nature, it is often said that parkour is in its own category.
Practitioners move not only as fast as they can, but also in the most direct and efficient way possible; a characteristic that distinguishes it from the similar practice of free running, which places more emphasis on freedom of movement, such as acrobatics. Efficiency also involves avoiding injuries, short and long-term, part of why parkour’s unofficial motto is être et durer (to be and to last). Those who are skilled at this activity normally have an extremely keen spatial awareness (a.k.a. air sense).
(h/t to Kaiser Kuo)