This pinball machine was introduced at a LegoWorld exhibition a couple of years back and I have found it now.
Of course pinball needs a round ball, so it was not made of Lego but everything else was. The creators have used 20000 bricks. It works with a 50 Eurocent coin, it does not accept other coins. The player gets 3 balls but there is a lot of chance to get extra ones, for example by landing in the black hole or get all letters from the P-I-N-B-A-LL sign. Rotating arms and auto-kickback make the game more interesting.
The game is controlled by 13 RCX units (Mindstorms computers) and all of them were needed because one has only 2 inputs and 3 outputs. 4 controls the display, 6 the point collector, one the flippers, one the new balls and one the auto-kickback. The table contains 50 lights and 24 motors.
The creators claim it took 300 hours to assemble. You can read more here.