I picked up a Malekko Omicron Spring at a local shop yesterday. I really like the sound of it. It's not quite as warm as the real thing but is pretty dang fun!
http://images.lilypix.com/albums/use...20Spring_1.JPG
It's tiny! It does not take a battery it would kill it pretty quickly, anyway.
http://images.lilypix.com/albums/use...o%20spring.JPG