Check this vid out http://www.youtube.com/watch?v=pu-12IOBRiI and http://www.youtube.com/watch?v=HpQvQ0Gvq4U
it was originally created by the french and is called Parkour, they have thier own site. Its really cool and has been posted many times, a while ago now the best of them did a TV show and were basically doing thier stuff all over london.