Great advice.  This is a tremendous problem.  I believe asking the team members to each give a report/update and require others to give input to that member might help facilitate listening.  The meeting leader also needs to lead by example and address the issue at the start of the meeting.  I have yet to attend a meeting where someone had to step out for true emergency.  You brought up a great point saying if it's so important, share it with the group.  Success relies on the leadership truly leading.