touchscreen - How can I record touches?

Is there an existing app I can install that will record my touch interactions in the background? I just saw this and it made me want to play around with my touch data to see what it looked like. Didn't turn up any likely candidates here or in the Market. Google seemed to indicate that it is certainly doable if you write your own foreground app (which I have no interest in doing because I want to record my touches in the entire system), and that it might be possible using a custom-developed background app, which might be a fun project but I'd rather install an existing app if possible.