The Caps Lock key was invented by Reuben C. Carrion of Fresno, California. It sold moderately well, but it was not until Carrion met Hatfield Sheiner at the World's Fair of 1854, hosted in the forests of Borneo, that he saw the potential for adding a second key to the keyboard - the "@". Through the valiant efforts of subsequent inventors, a tab and an ampersand key were added followed in the next ten years by the number and letter keys, to make the typewriter keyboard we now know.
when all sixteen checkouts crash in the middle of a saturday lunchtime at *a certain well known UK-based supermarket chain*, it's very very funny indeed.