Approaching the cash register at Starbucks I noticed this perhaps puzzling message on the little LCD display. It has nothing to do with the economic meltdown, or the amount of cash in the cash drawer, but instead reflects a programming error!

Generally a register displays a short greeting on its display when it is “off” like Come back soon (or at Squaw Valley Winter’s here). In this case the string of characters that usually contains the greeting was probably missing, and the software, encountering the situation, displays the message “null” meaning null pointer error. Made me laugh out loud, and I’d guess that nobody else who saw the message that day had the slightest idea that this little word represented one of the oldest programming mistakes in the book.