I should add this: One thing that's been on my mind is how bluegrass banjo technique can be used to add something new to tunes from entirely different traditions. I've been working up a version of Bob Marley's "Redemption Song" that sounds surprisingly folky and rhythmic, and pretty as hell too. Another one I've been experimenting with is a Puerto Rican party song called "Elena," which had a long life as a folk song before it was recorded as a salsa tune by Manny Oquendo's  band. That one works really well in A minor with the "mountain minor" tuning. Now I'm thinking about a merengue tune to take up -- it seems like that kind of a beat could translate nicely into the oom-pah feel that you expect in bluegrass.