I'd hesitate to hop on this without some type of scientific HUI study...
I bet you're right, this thing would not work well in the real world. Sure does look space-age though
Pentimum - the spaceball is very comfortable to use. If you come across one, grab it.
This thing :
might make a comfortable mouse replacement ... after using a spaceball, something more fluid than a mouse is appealing. I'd love to be able to go left right up down in out from a single device. Xsgi has the Xinput extensions, too. Hmm ....