New York 2008 from Vicente Sahuc on Vimeo.
EDIT: I should have included the attribution - I found it on http://procrastineering.blogspot.com/2009/02/wonderful-slow-motion-stabilized-video.html which I clicked through to from the screamingly funny (but not NSFW) Penny Arcade cartoon on Project Natal (later known as Kinect) http://www.penny-arcade.com/comic/2009/6/5/.