I recently watched a Celtic fingerstyle DVD and started messing around with the Orkney tuning (CGDGCD). It's sort of a messed up tuning but sounds very pretty. The low C and drone ability makes coming up with phrases quite easy. Capoing up the third fret makes things sound sparkly but you still have a good strong bass ring.
For those interested in trying it, tune your guitar to an open G (DGDGBD) then drop the 6th string another step and tune your 2nd string up a half.
I'll post some clips of what I've been working on when I get the chance.