Yesterday, one of the NBC Sports commentators--it might have been Jim Lampley--said that some of the NBC Sports staff figured out how long, in actual length, Phelps' winning margin was in the 100 butterfly, where he won by a hundredth of a second. Here goes--take a common pencil. See the metal on the eraser end, and the eraser? It's less than an inch. That was how much Phelps' half-stroke got him as a margin of victory.
It could have been 90 meters, for the result. And it was less than an inch.