Put both hands on the keg. Wrap your thirsty lips around the tap, open it, drink. Keep track of your time. Compare times with yor friends. Oh yeah, shake your head to signal somebody to close the tap.
Participation is mandatory.
A simple game, could be quite interesting. A game that could very easily be played in a bar, making the lives of others more interesting. Played with liquor not beer. Shuffle the cards. Start dealing one card at a time, face up, to each player.