Simply a simple game with a pretty high buzz factor.
Simple supplies: people, beer, deck o' cards.

One player goes first. Using mental telepathy, s/he tries to predict the color of the card about to be turned over. If correct, s/he continues; if incorrect - drink.

If correct three times in a row, the player can make a rule concerning procedure for the game. Interesting rules are:

• "Can't say red"
• "Can't say black"
• "Tap head before drinking"

As always, be creative.

Of course, if some is caught "violating" a rule, s/he drinks. But be sure not to break the rules while enforcing them.