It's 10:20am as I'm posting, so fortunately my breakfast is pretty well digested, and I still have an hour or two before lunch. You probably wouldn't want to view the linked Zombie photo-essay, on the "Naked Bike Ride 2006," in San Fran of course, if you were in the process of eating, or in the immediate before-and-after period.
As Zombie wonders in one of his comments, you have to consider the very real possibility that most of these people are just exhibitionists, once forced to wear raincoats around in public, the better to flash their wares at children and unsuspecting citizens of all ages. These staged events give them "legitimacy." The guy with the Happy Face sticker, I can practically guarantee you, has a record of indecent exposure and/or sex offenses. Where are the cops?! Do they even have cops in SF?
Funny too, to me at least, was the "sex symbol" of the parade, the dumb-looking girl with the fried-egg boobs. Lastly, I will never worry in the slightest about my penis-size again, no matter how cold it gets, how fat I may get, or even if I develop scrote-cancer and need to have parts removed. Not that I was ever worried, heheh.