Like many people I consider cities as a giant playground. Amsterdam seems to be particularly suited for this role. Skateboarders and rollerskaters have more or less pioneered the urban playing aspect of cities. Now also the more conservative sport of golf is turning towards playing in public city parks. At least the Vondelpark in Amsterdam was temporarily altered into a public golf course last Tuesday. I was wondering if litigation laws in the US would permit such a sport like golf to be played in a truely public park. Surely it is played with hard litte balls, that travel at fairly high speed, that can essentially hit unexpecting pedestrians in the park. Question to the blog visitors: what other sports do we see taking themselves into the public domain? Do you see innovative businesses being built around them?