Hello.

Martin McClure of GemStone fame gave a very nice demo of "virtual
juggling".  In order to do that, you have a machine showing objects in
the machine's display.  The objects follow some sense of law of gravity,
so they tend to fall down.  You project the display to a projector
screen.  You also attach a camera to the same machine pointing to the
screen, so the machine can determine where the objects are in the
projected screen.  When, according to the camera, someone touches the
objects, the objects bounce -> virtual juggling.

The original was implemented in C++, but Martin implemented it in
Squeak.  Martin also showed the following hilarious video during the
presentation.

	http://web.media.mit.edu/~vigoda/karamazov/shadow.mpg

I'm not sure whether the video was made with the original C++ version or
with the Squeak version, but it gives an idea of where Squeak is being
used and how it would look.  Notice the camera in the bottom center of
the screen.

Andres.