At Educom in October 1988, I was running rotating demos of NeWS, pie menus, Emacs and HyperTIES on a Sun workstation at the Sun booth, for whoever walked by.
Ben Shneiderman and I pinned down Steve Jobs and led him over to the Sun booth. He jumped up and down, pointed at the screen, and yelled "That sucks! That sucks! That sucks! Wow, that's great!"
The Hubble Space Telescope database had pop-out targets on every instrument. The other demo was The Founders: a photo of Sun's three founders, whose heads popped out when you pointed at them, and all at once when you clicked the background. Kind of like what they call "Big Head Mode" these days. The heads are PopupTarget regions, and clicking the background is Reveal all links.
The best part of the demo was when I popped up all the heads of the Sun founders at once, by holding the optical mouse up to my mouth and blowing and sucking into it while secretly pressing and releasing the button, so it looked like I was inflating their heads!
One guy hung around through several loops of the demos, and by the time I got back around to the Emacs demo, he finally said "Hey, I used to use Emacs on ITS!" I said "Wow cool! So did I! What was your user name?" and he said "WNJ".
It turns out that I had been giving an Emacs demo to Bill Joy all that time, then popping his head up and down by blowing and sucking into a Sun optical mouse, without even recognizing him, because he had shaved his beard! I always thought he was more of a vi guy.