For those of you who never heard of parkour or free running, here is the definition of it, via Wikipedia.
Parkour is a discipline, more similar to a martial art than to a sport, focused on moving from one point to another as smoothly, efficiently and quickly as possible using the abilities of the human body. It is built on the philosophical premise that any obstacle, physical or mental, can be surpassed.
Parkour can be very entertaining when done right, my example of that is this video. Unfortunately, I didn't get a lot of videos of guys successfully pulling of parkour tricks, I did you one better, I got guys that tried to do parkour tricks and failed. Thanks to gorilla mask for posting the video that inspired this post.
Here are 15 more hilarious videos of people who need to train a little bit harder at their parkour skills.
This guys head hit the pavement pretty hard... ouch...
Roof Jumps are cool, as long as you make it to the other side.
Here is an example of what happens when you give in to peer pressure.
This is why you rarely see fat people doing parkour.
Maybe a little more spin would have helped.