Another interesting concept at SIGGRAPH is called 'Demo or Die'. The premise is as follows:
* you have to conduct a live demo of whatever gizmo you've cooked up.
* you get three minutes to present it
* After your demo, the audience gets to vote.
Now the voting itself is a neat idea. The organizers distributed laser pointers (yes, over a 1000 of them) to everyone in the audience. There was a large screen up near the speaker podium, and after each demo, two large boxes saying Demo and Die were broadcast on the screen. You pointed your laser pointer at the screen (these are very powerful pointers) and with some nifty software/hardware, the number of dots on each side were tallied to decide whether the presentation survived or not.
Surprisingly enough, the Law of Demos only kicked in once; most demos ran seamlessly. Which is not to say that they were all good. Some were quite nifty, involving haptic devices.
An amusing moment: A demo participant from Microsoft showed a haptic device for playing Jenga online. I had dinner with him the night before, and he was describing the demo to me. I couldn't help but remember Uri Zwick's talk on Jenga from SODA 2002. It seemed fitting that we prove theorems about Jenga, while graphics people build demos about Jenga.