When I'm on the shuttle I like to look at people. I will pick a person and stare at them until I find something of interest, whether it be a particular facial feature or body part or item of clothing.
Then I will feel the compulsion to look at the same thing on all the other passengers and do a study in compare and contrast. For instance, on the way home today I looked at chins. Weak chins, big chins, long chins, short chins. Amazing how a chin completely defines a person's profile.
Then I take what I learned from "Extreme Makeover" and give people imaginary chin implants.