How can a Board member who is facilitating a meeting, also have meaningful input to the discussions? (This happens often when Board members, who have facilitation skills, volunteer to lead the discussion.  But they also have value added contributions to the discussion as well.  Do they have to exclusively only fill the facilitator role?)

Answer: 

It is fine to switch between facilitator and participant during a meeting, as long as the group knows when this is occurring. During the specific agenda item, announce to the group, "I am removing my facilitation hat and giving it to Jane for this item so that I can be a participant in the discussion." Further, it would be helpful to plan for this switching of facilitators in the meeting preparation phase and identify and brief the person who will be the temporary facilitator.