NO PANTS DAY, NEW YORK CITY

Naked truth: Imagine it's the first Friday in May, and you're in New York. You're taking the 2 train to Times Square, minding your own business when you look up and—ka-pow!—half the subway car has dropped trou. Actually they boarded the train that way—fully dressed from the underwear up and ankles down. But there's no need to flag down a cop. The harmless truth is that No Pants Day was started by an improv troupe to provide some comic relief to bored commuters (check out their Web site for hilarious videos). It has since spread to other cities—from Boise, Idaho, to Adelaide, Australia—and other bored commuters.

Bodies of evidence: What New Yorker hasn't passed a long train ride checking out foxy fellow commuters? No Pants can be a (day)dream come true, when that buttoned-up businesswoman or that hot hipster across from you promptly disrobes. But there are all walks of (pantsless) life here, so generally it's more of a laugh than an aphrodisiac.

Best reason to bring a towel: Remember, this takes place on the New York City Transit system. The towel is for anything you plan on touching with any part of your body. In fact, it's not a bad idea to bring one with you on a fully clothed subway ride.

Don't forget your: Metrocard. Nothing will take the fun out of the day like having to jump the turnstile with no pants on. The cop in the station won't think it's so amusing either.

NEXT: Undress for the environment >