I'm slowly decoding the catalog of instrumental weirdness that Buddy Miller unveils on that Plant/Band of Joy DVD I've been raving about.
One thing that caught me out was what I first thought was an electric mandolin. But it had rather too many courses of strings. So some searching dug up this
Which is a mando-guitar. Like a 1/2 size 12-string. It plays in the mandolin range, but a guitarist doesn't have to learn different fingering.
Apparently the first such instruments were launched by VOX and look just like this one. I'm thinking that maybe VOX licensed it in various territories. You get lots of different names on the headstock but they all look the same. Some may be contemporary copies.
He's also got some unusual semi-acoustic which I have yet to identify. No matter, he kicks up a totally wonderful noise with all these unusual instruments.