The No Pants Subway Ride is an annual event staged by Improv Everywhere every January in New York City. The mission started as a small prank with seven guys and has grown into an international celebration of silliness, with dozens of cities around the world participating each year. The idea behind No Pants is simple: Random passengers board a subway car at separate stops in the middle of winter without pants. The participants do not behave as if they know each other, and they all wear winter coats, hats, scarves, and gloves. The only unusual thing is their lack of pants.
The 12th Annual No Pants Subway Ride will take place on January 13, 2013. Details here.
This info have i get from there website: http://improveverywhere.com/missions/the-no-pants-subway-ride/
If you wont to be in this even you can find the information you need bay visiting this web page: http://improveverywhere.com/2013/01/07/no-pants-subway-ride-2013-details-for-new-york/#more-4763
There homepage there you can find lots of information: http://improveverywhere.com/
I wish every one that are going to be in this good luck.