From Charlie Todd of Improv Everywhere:
While the 7th Annual No Pants Subway Ride is happening in New York this Saturday, there will be seven other No Pants Rides held in cities across the world. Here are the details for all of the regional events:

New York: Details available on ImprovEverywhere.com
Boston: 3:00 PM, Sharp! Location: Meet at ALEWIFE STATION, Indoors. You can park there ($5) or take the subway out to Alewife, but we will be meeting just before the platform, downstairs, in the large open area. If you are coming from the parking garage, you will have to purchase your subway ticket and go through the turnstiles first, and you will see us. (MAP) Bring: A backpack and a charliecard/cash.
Washington DC: 4:00pm – Location: Dupont Circle fountain.
San Francisco: 3:00pm – Location: across the street from Embarcadero station
Portland, OR: 4:30 PM – Location: at the park by Lloyd Center MAX stop
Chicago: 2:00 PM – Location: Loyola CTA Red Line Stop (Arthur and Sheridan)
Adelaide, Australia: 12:00 PM – Location: Train/Tram leaving city
Toronto, Canada: 3:00 PM – Location Bloor Street Boxing at 2295 Dundas Street West (meet there and then walk to the train.)
If you don’t see your city on the list, and you have a subway or other form of mass transportation, then start your own event and post the event link on the wall of the Improv Everywhere facebook group.
In other news, Improv Everywhere will be featured this Friday night at 10 PM on ABC’s 20/20.
Related links:
Your Mission Should You Choose to Accept It: 7th Annual No Pants! Subway Ride
No Pants 2k8
Improv Everywhere: Shirtless at Abercrombie & Fitch
Mp3 Experiment Four
Improv Everywhere Redheads
Starbucks Pranks