What tuning does he use here?
 

http://www.youtube.com/watch?v=-fe1G...eature=related

Its a video of 16 Horsepower (great band) doing an acoustic version of their song Poor Mouth. The chords for the verse are: Gm D.
With that in mind, could anyone tell me what tuning either guitarist is using?
In fact, could anyone tell me if ive even got those chords right? Im pretty sure theyre Gm and D, but they just sound a little different when he plays them (this may of course be because he's using an odd tuning)

Any help would be greatly appreciated.

Back to my dissertation now...

Just had a listen and I think you're right about the chords. If there's a slight difference it's possibly because the chord voicings they're using include some inversions.

As for what the tuning is I can't help you there but try drop D, double drop D, or maybe an open D tuning.