We were making pizza tonight (C rolled out his own, and spread the toppings with only a little help) when something unexpected happened. Maybe the stone was too hot, maybe I just discovered and lost the secret of pyroclastic flow, but whatever it was, the second pizza left the peel and just slid across the stone and slumped off the back end. No amount of fancy peelwork was pulling it back on, so I pulled the stone out from under it and left it bake on the bottom rack while the stone went to the top (Because no way am I just plopping 600+ degrees of stone on the counter).
When I went to check on it a couple minutes later, the pizza had pita'd up into and almost-perfect half sphere, and you could hear the occasional thump-hiss of pepperoni, yellow pepper and cheese falling off the edge of the world onto the bottom of the oven. It seemed like a good time to put it back on the stone.
The end result was reasonably edible -- the center deflated again, leaving a nice high puffed rim, and the cardstock-thin charred bottom crust just peeled right off. But now I'm sort of wondering if one could do this on purpose, at least for the visual effect. With enough convection heat you might even be able to get it to set. Then just a matter of securing the toppings against side forces...
Sadly we were too full to eat the last pie of the three, which was mozz on top of pesto on top of mushrooms and onions sauteed in olive oil.