I stumbled onto something, and as cool as it looks, this should really not make it into JOGL production, without some way to shut it off.
I was not having a good day yesterday trying to get my first fragment shader to compile. FYI, I am hacking OpenGL to trick a video card into becoming a co-processor, to speed up a multi-trillion instruction program I have. Anyway, at one point I went to the JOGL demos page, and ran the Vertex Refracture demo, the one with the bunny, just to make sure everything was still right with my system. Finally, got it to compile.
Today, I see the jnlp file on my desktop, and I run it again for the hell of it. I tried to close the window, using one of the thumb mouse buttons I had programmed to type Option-w (on OS X that closes current window). Suddenly, the building background was gone, and the bunny was now wire frame. Click again, and it goes back to normal. First I thought it was an Easter Egg for that program, but all the demos which use a vertex program have some kind of change when you type this. Went to my windows machine, and it does something similar with Flag-w, but you have to hold it down.
Probably a nice diagnostic for development, but it should probably require enabling by the developer.