Programming Warm Ups?

ResHippie asks: "No athlete or musician would think about just diving in to the day's activity without doing some series of warm ups first. Aside from starting most computing sessions with checking email and the like, I pretty much try to dive right in to the task at hand. It usually takes me a while to get going, though. Does anyone have any routines they go through before coding (or any other work-like activity) that helps?"