There's always the 'identify the stuff in the diaper' game. Take several diapers and put different melted chocolate candy bars in each diaper. Pass around each diaper and the guests have to guess which candy bar it is. This is especially good if the guests don't know each other very well, because there will be alot of 'ewwws' and 'gross!' and laughter. I've never yet seen people not bond during this game!