We are also thinking about seeing Penn & Teller. Hubby has mentioned it before but they've never been on the last few years when we've been there. They seem to take their holidays at the same time as us!
I printed a coupon from the web, but I can't honestly remember where from. I don't really know whether to book or wait till we're there in case we don't want to over-plan. We've been run off our feet with the move and diy etc, so the last thing on my mind is planning things precisely right now, as my experience of planning these days seems to be that it doesn't really work out anyway