Synth Zone has links to Stylophone websites, so I'll include them here.
Rolf Harris used to use one back in Australia.
A brief history
http://web.archive.org/web/20020314060850/members.aol.com/normleete/keyspage/dubreq.htm You can still buy them here
http://www.stylophone.com/ A free VST Stylophone plugin
http://www.kvraudio.com/get/68.html