THE TASK IS SIMPLE but impossible. You are standing on the 50-yard line inside the Louisiana Superdome in New Orleans, and your job is to tile the field with 1-inch-square bathroom floor tiles, half of them black, the other half white. Billions of tiles await you on wooden pallets in each end zone. And so you begin. One tile. Fifty tiles. Ten thousand tiles barely cover the insignia at the center of the field. So far to go. It hits you that if you are ever going to finish with your sanity intact, you'd better start making this job more...