http://www.nytimes.com/2009/01/18/jobs/18pre.html?8dpc : Meetings are a Matter of Precious Time
One thing I know now is that once a meeting has gone off in the wrong direction, it’s difficult to bring it back on track after only 10-15 minutes of intoxicating, aimless chatter. Taking the initiative to define the PAL (Purpose, Agenda, Logistics) within the first five minutes probably saves ten times that time it takes.