Freestyle walking is a relatively new 'sport.'
I say sport in inverted commas because it is not exactly a sport, but more of a physical recreation.
Free-walking evolved primarily out of Soap Shoes which didn't really take off but were shoes with a strip of plastic on the sole so the wearer could slide down seats, poles etc.
Free-walking is similar, but you can do it with any shoes, or even without shoes. You simply walk along anywhere and do tricks.
Some basic tricks are things like grabbing a pole and swinging round it, any on ground gymnastics, heel clicks, slides, jumps etc.
The concept isnt as simple as that though, first examples of freestyle walking can be seen by people like Fred Astaire, Charlie Chaplain and other dancers or slapstick comedians.
More contempory influences include things like the breakdancing, especially things like uprocking and ground work.
More diverse than it may at first seem, freestyle walking is on its way to being a pop culture, it is associated with commercial products and moving to global popularity, although its still in a cult status.