I have seen skateboarders performing some extremely difficult movements on the street. I always thought that they perform on the street to get people's attention. However, I was amused when the author of this article states that skateboarders interpret the city in a different way by choosing the "left over" urban space to do their sport. I am not sure if this is really to "appropriate public space" or it's just to practice at some corner that won't been seen by the others.
However, it is interesting to think about how the urban spaces are viewed by different groups of people. For example, the same city "looks" and "feels" different from the eyes of it's dwellers than from the travelers. Because of the difference in each individual's relation to the city, the spaces are interpreted differently.
When I was reading this article, the Parkour came into my mind. Unlike skateboarders who explore the terrain of the city with a board, parkour practitioners use their body to move among the architectures in a very styled way.