Interesting concept here - the Electro Faustus EF110 Blackfly Metallic Swarm Gnerator has four springs and a kill switch which allows you to twang the springs for some mad atmospheric sounds. Pop it through a few pedals and things get very strange very quickly.
Their description sort of sums it up nicely:
The Blackfly is a spring activated instrument that delivers a wide spectrum of sonic textures. A secret weapon for serious noise makers, soundscape architects and spacious jam explorers alike!
One of the more unusual concepts we've seen for while. priced at $159.