If you want to sneak up on someone who's getting drowsy, approach him from the left. Even if he hears you, his brain may interpret the sound as coming from the right.
I'm sure this should help us win elections, too.
CWCID: As always, when I start talking this way on a Saturday, I'm responding to a variety of excellent links from Not Exactly Rocket Science. Some weeks, it's unremitting PC nonsense, but the pickings are good this week.