A very mesmerizing art for about 1/10th?
of the population. 9/10ths?
will simply not be interested.
That's an exaggeration (the 9/10ths? thing). Some of those 9/10ths? will think it looks pretty cool, but not stop everything they're doing and watch you with a mad gleam in their eyes.
It involves making a ShinyThing
in the shape of a 3" diameter clear (or eerie flourescent under black light) acrylic ball roll around ones arms and torso and even entire body. Lots of fun.
A good (the only, sans ici) webpage on ContactJuggling
can be found at http://www.contactjuggling.org