Here's a fun game:
Whenever you see someone look at their watch, wait until they stop looking, give a silent one second count, and then ask them what time it is. If they look back at their watch, you get a point. If they are able to tell you without looking, you lose a point. At the end of the week, add up your score. If you score in the negative, that's how many seconds you have to leave your tongue pressed against the terminals of a 9 volt battery. If you score in the positive, you're allowed to beat on someone for that many seconds.
Try it!