What is the art of jumping from building to building called?

We've seen some extreme athletes doing this, like David Belle. The tag for the activity is urban obstacle coursing. Belle's position is that the urban landscape is, in and of itself, an obstacle course. So he treats it as such, and with extreme athleticism. Use the links below to look at a couple of short clips of Belle in action. (There are more in the Related area.) Wimpy people need not apply for this kind of gig.