Anyone use a pizza stone? I recently ordered a Pampered Chef rectangular pizza stone. The rectangular stone was the only flat model they have now. Everything else has 'handles' built in to the stone itself. I was told by my friend that its best to "season" the stone by baking greasy things for a while, like canned biscuits and cookies to build up a non stick surface before using it for pizza. Also, what about frozen pizzas? Is it ok to put a frozen pizza on there and put it in a hot oven (450F)? Do you preheat the stone, then put the pizza on it? Or build the pizza on a peel, then transfer to a pre-heated stone? Any suggestions or comments are appreciated.