No Pants!? 2009, Saturday January 10th

Hundreds of people do this on the New York subway, and it's spread to cities across America and around the world. On a January day, so-called agents show up in normal clothes minus pants, and ride the subway train as if nothing was wrong. It's very popular in Washington D.C, San Francisco, Chicago and Portland too, with around 2,000 pantless participants taking part across the nation last year.

The bizarre idea comes from Improv Everywhere, a New York based group who say their mission is to "cause scenes of chaos and joy in public places". They've been riding the subways annually without pants for seven years and from the reports on their website, it looks everyone is having a fun time.

Men and women participate, wearing all varieties of underwear, frilly bloomers, polka dot boxer shorts and tighty whities. It's not about nudity - underwear is mandatory and thongs are prohibited - it's about the prank. The joke is that everyone pretends that they just forgot their pants, and pretend to be unaware of the other riders without pants. There's video of past events on Improv Everywhere's website, and some of the reactions of the other people on the trains are priceless.

Are they insane? Or are they fun loving individuals and you want to join in? Local improv organization Plan B Minnesota are hoping you will, and come and ride the light rail with no pants on Saturday January 10.

• Mission Report from No Pants! 2008, New York
• Plan B Minnesota: connect with other people who want to ride the light rail with no pants either.