Have you ever pressed either of the shift keys five times really fast?
I sure wish I could reassign that function to something I can use.
By the way, I have known about it for a long time, I was just wanting to see what happens when people that do NOT know about it, read the question and then answer. Sort of like standing on a sidewalk in a crowd and staring up in the sky. After the first few people start looking up it causes a chain reaction. You can then stop and watch.