These are interesting things I've found on the internet.
eBay of the day: Megaphone Helmets
eBay of the day: Megaphone Helmets: " Just look at the picture. There's really nothing more to say. A pair of immeasurably awesome megaphone hats from the 1950s. Includes a pair of shoulder-mounted battery packs which can also be used to transmit morse code through the hats. Ebay item #6045938976, 5 days to go, £45 starting bid. Awesome. (Thanks Richard)