Ballerinas are nice to watch, sure. But they also do insane things to their bodies to maintain what has to be an unhealthy physique. What if there were regular folks who lived how they wanted and could still move awesomely? I don't know about you, but I'd wanna watch that video posthaste.
Is there a parkour certification process? Classes, levels, belts, that sort of thing? Before a parkour artist (parkour-er?) begins, can we see proof of accreditation? That way we could maybe stop people from hurting themselves so badly. 'Til then, we can enjoy the videos.