in 1996, the norwegian artist reidar finsrud revealed his near-perpetuum mobile.
a steel ball [about 7 cm, 9 kg] is rolling on an aluminum track, about 63.5 cm in diameter, placed horizontally. three pendulums, about 115 cm long with tunable weights at the lower end, controls three horse-shoe magnets that the steel ball has to pass by on the track. embedded in the track is a [mechanical] controlling/timing mechanism. it looks like a steel wire bent into a triangular track, 13 cm long. the ball rolls over it and pushes the wire down through a slot in the track. this affects one of the pendulums and regulates its swinging motion. the ball has been reported to move for many days uninterrupted.
read a wiki on the history of perpetual motion machines.
watch more detailed [45 min.] videos [ 1 ][ 2 ].