These controllers were originally for use with the Sony PSone for kids in Japan. However, as with all Playstation controllers, they can be adapted to connect to PCs via the USB port. Could be useful for someone out there, especially if using JoyToKey with it.
As a side note... I tracked down a site called Hirau Potter Net (great name!) - which has quite a few interesting electronics hack projects to look through. Added this to my D.I.Y. links.