Just as the original posters (produced by the Ministry of Information in 1939) were made to get the message across loud and clear to a Britain in the middle of World War II (although they weren't actually seen by most of the British public), these necklaces put that same message out there, and funnily enough, it's a message which seems just as applicable 70 years on...
Made by Etsy seller IMCreations, the message is stuck onto the back of Scrabble tile and comes in a variety of colours - from celery to pink to plum. They're priced at a very reasonable $6 (not including shipping) but if you buy three pendants, you get to choose a fourth for free. Great pressie idea and there are other fab designs to choose from, too. Check out the entire Etsy shop here.