David pointed to Fantastic Contraption which is obviously a subtle plot by some terrorist organization to bring the productivity of U.S. workers to a grinding halt.
The boys and I used to love The Incredible Machine (I even miss the intro theme), the game on which Fantastic Contraption is obviously modeled. Likewise, my dad and I loved Rube Goldberg cartoons (one of the Christmas presents I remember most vividly was a catalog from Goldberg’s 1970 exhibition at the Museum of History and Technology). I wish I could clear away the whole long list of tasks that need my attention, so I could devote a whole day or two to these entrancing puzzles. (By the way, the third level took me long enough that I realized I needed to quit for the day and get to my real work).