Unusual Microtonal Instruments

I could use some help with some research. I just got an email from a
British television show that is interested in doing a segment on
unusual instruments. I will probably be having a telephone conversation
with one of the researchers. I think I'm being consulted because of my
blog on ancient instruments. <http://lutesandviols.blogspot.com/> I
have a lot of ideas, but I would like to also mention some unusual
instruments that are specifically designed for microtonal music. If you
can provide some examples or links, it would be appreciated.

I don't know if this will amount to anything. I know someone else who
assisted with a similar type of research and his information was pretty
much ignored in the end. It seems like it might be fun to collect this
information anyways.

Thanks,
Daniel Thompson