Insurance. Not too long ago at KDTU, I was taping from seats. During the last song before encore, I'm standing w/ my eyes closed, head dancing, completely lost in the music. I don't know if the guy next to me slipped on the spilled beer wet floor or spazzed out or what, but he body slammed me so hard that I was knocked hard into my stand. I caught it, luckily, but knew that that was going to be recorded for posterity. Suprisingly, unless I'm studying it w/ headphones, I can't hear it.
Moke, I use 3>4" squares of 1/4" antifatigue floormat foam under my stand. It may help with vibes, is good for leveling on the sloped floor, and prevents slippage. Don't see anyone else doing it though.