As you can tell from the picture, these speakers are dead skinny. 0.9mm thick, to be exact, making them perfectly-sized for cellphones, cameras and other portable gadgets which may require all the parts to be waterproofed.
Murata, based in Kyoto, Japan, created what they're calling the world's first "ultra-thin waterproof piezoelectric speaker," which is said to be cheaper than the usual waterproof speakers found in Japan, thanks to the way the output holes have been waterproofed. Normally speakers are covered with waterproof "sheets," which cover the output holes—understandably reducing the sound quality, but also proving costly to create. Murata gets around that problem by getting rid of the waterproof sheeting altogether, instead redesigning the speaker holes entirely.
Waterproof phones are pretty popular in Japan we hear, with Murata claiming that around one in four phones released in Japan last year were actually immune to moisture. They're on sale to manufacturers now, at around 250 Yen ($2.70) per unit. [Murata via Akihabara News]