I was doing research for my Mac history podcast</shameless plug> when I found something in my archives that seems to have dropped off the web. I've uploaded it for future generations:
Bill Atkinson demonstrating his baby, HyperCard 1.0, in front of the Dallas Apple Corps MUG. I no longer have the original metadata, but it seems to be from 1987/1988 judging by the third-party stacks he demos.
Enjoy.