In the old days everyone used to post about meetings and techniques for meetings. The old days, ten years ago in the blogosphere.
Original tweet here. You could easily start meetings like this. We are here for X reason and we can leave when we have achieved / decided Y. It would also be a brilliant way to start a presentation. Workshops. Business lunches. Kids parties. Anything.
In the old days of the blogosphere Innocent used to have this on the meeting room doors. It's similar to above but longer and has a more friendly tone.