......and an "inside glimpse" , a brief look about some constructive details of a wind kinetic sculpture , playing unbalance , at :
  http://www.youtube.com/watch?v=gQ3jHgH3SoE
Kinetic sculpture art , can help us to develop some ideas regarding the continuous motion due to the natural flow ("fall") of motion (energy)..
So , if we succeed the first workable test of a gravity powered device (playing continuous unbalance ,due to gravity fall and inertia ) , the next step follows...in the huge domain of possible arrangements ,thinking about the existing cosmic models playing alike (variable/oscillatory leverage).
   Al_ex