an adjustable tab or airfoil attached to a control surface, used to trim an aircraft in flight.
in other words,
a rudder for a rudder too large to be turned directly.
a lever to move a larger lever,
a leader capable of lead otherwise stubborn leaders to action
Also, an open letter to the Canadian government, in advance of the global climate meeting COP21, on the part that we at LightSail are trying to play.