Johnny, over at Spoon & Tamago is currently doing a preview of the Good Design Awards (happening at the end of the month) and pointed me to one of his personal favorites so far; the Fresh Label.

Design studio TO-GENKYO proposes a new method of tracking a foods expiration date by using a universally recognizable visual. Over the last year or so Japan had been struck by a number of scandals involving food companies tampering with expiration dates. The new design keeps people honest by changing colors based on the level of ammonia the food emits as it ages. After it has passed its expiration date the barcode is no longer readable, making it impossible to sell.