He tapes the desk with a template so that he can place the stuff in the right place. The pad and keyboard weren't taped down at WCG, obviously since people were getting up and sitting down when they needed to play also.
Huh. I wonder how he's able to get that smaller mousepad to stay in place like that then. After about a week or so of regular quaking I'll notice my raindrop xl has shifted in a couple inches in a couple different directions, and I use quite a bit higher sens than he does.