Have biggest rip contests, longest hold contests, play truth or dare where if you don't sink at least half a cone you have to complete a dare or tell the truth about something someone asks you and if you're horny play the stale game where you take a hit and have to mouth-mouth shotty it to the person next to you, then pass the bong and the next person does it. When you've done a whole circle you all move around to different positions. Those are all good fun, and I'm sure there's more but i can't be fucked thinking of them at the moment.

Peace