And you thought nothing good could come out of France ;-)
The Wikipedia entry starts:
(Le) Parkour (sometimes abbreviated to PK) or l'art du déplacement (English: the art of displacement) is a physical art of French origin, the aim of which is to move from point A to point B as efficiently and quickly as possible, using principally the abilities of the human body. It is meant to help one overcome obstacles, which can be anything in the surrounding environment — from branches and rocks to rails and concrete walls — so parkour can be practiced in both rural and urban areas.
That definition leaves out the coolness, so let me help you with that ;-)
First video to watch: David Belle, the leading light, in a chase scene from a movie.
One of the first things I thought: 'Parkour' resembles 'Parker' of Spider-Man fame. I'm sure this comparison has been made before.
In fact, upon watching these videos, Wil said 'That guy's like Spider-Man.' ;-)
More? this compilation
Finally (for this post), 10:43 from a French documentary .