The dishwasher! The perennial optimization problem. Even the chronically untidy have been known to harbour strong opinions on efficient loading technique. But did you know dishwasher manuals actually include photos and illustrations of ideal rack layouts? (Be honest -- did you even realise your dishwasher had a manual?)
Joe Clark "downloaded one or more instruction manuals from essentially every dishwasher manufacturer in existence [the above diagram is from a KitchenAid manual]... extracted just the pages or parts thereof that illustrate how to load the dishwasher, and assembled them on Flickr."