Sit in a circle, one fewer chairs than people.

Person in the middle says, "Have you ever ..." and adds something. The only rule is that it has to be something they have done, so for example, depending on the group it could be as harmless as "Have you ever - been to Sydney" or as risque as "Have you ever - made love on a beach."

Everyone who has done this has to switch to another seat - and not the seat next to themselves.

The person in the middle has to try and get to one of the seats first.

The hidden rule - that you don't tell at first - is that if NOONE moves, then the person in the middle has to tell the story - this will hopefully be interesting since its something noone else has done.