Helge made an interesting LEGO clock that uses ping-pong balls and Lego Technic to keep track of time. One thing that makes this clock different from the rest, is his way of transporting the balls to the top of the clock.

Every minute a fan starts up and blows a new ball from the reservoir at the bottom, through the long tube and up to the uppermost tray.

If you happen to be in Trondheim, Norway, check it out – Link
Don’t forget to look at the “details” page – Link

Related:

A more modern looking LEGO Rolling ball clock – Link