Ok

Get a pint glass and make a skin of Rizlas that fits over it so it's taught like a drumskin.

Place 5 pence (or if you're in USA, then I suggest the smallest coin in your currency - a dime? or nickel?)

then, toke - and burn a hole in the rizla skin. The person who makes the 5pence fall in but can rebalance it takes a minor forfeit. I play beer bitch - you make the person fetch everyone's drinks until someone else knocks the coin in.

If the coin is knocked in and you can't rebalance it - then you make another forfeit. And this can be anything - a tin of baked beans poured over his head. He misses the next session, anything.

:-) It's so goddamn fun!