So I was at the dirty electronics workshop in Manchester with John Richards as part of the FutureEverything festival. We made this little toy, very simple but a lot of fun :) Simply contact with the plate from your fingers causes the conduction of electricity, and a mono out jack to output sound.
This sort of 'hardware hacking' is useful as it is bypassing a computer, so is 'standalone', save for needing to wire up to a speaker.
