You can wear fun underwear if you like, but nothing that screams out, 'I wore this because I'm doing a silly stunt.' Wear two pairs of underwear if it makes you feel more comfortable. Don't wear a thong or anything else that might offend people. Our aim is to make people laugh, not piss them off

Just as snow is forecast for London, it's time for the second No Pants Tube Ride or No Trousers on the Underground 2011 . The No Pants Subway Ride has been running in the US since 2002, starting on the New York Subway by ImprovEverywhere . It's now taking place in over 40 cities throughout the world. Rammi who took part in the event last year is organising this year's on the London Underground. Once again it looks likely to be a freezing cold weekend. However, on Sunday afternoon on the 9th January there'll be people casually travelling around the London Underground sans trousers. Last year over thirty people took part in London and there's currently over 170 signed up on the Facebook event page. There's still time to sign up, all you need is "".The aim is to be nonchalant and like the US riders to look as though you've just forgotten to wear trousers. Rammi says: "."Good luck to them, and I look forward to seeing any pictures or videos on Monday!- Over 100 people took part in the event. See what happened at No Trousers on the Tube 2011