Townes- Another bluegrass adaptation is Steve Kaufmann's signature G run: A# A G A A# B D E D G same as above, but start with 1st fret, Astring, and pull off, then 3rd fret 1st string...then proceed as with the classic G run.
Another adaptation is the McCoury run, which is a sneaky, Half-bar sort of fill (listen to "get down on your knees and pray")... It goes a little like this: G (rest, generally 1 beat, dragged to 2 sometimes) G A B F G Read as Estring 3rd fret, (rest), Estring 3rd fret, Open Astring, Hammer-on 2nd fret Astring, 3rd fret Dstring, Open Gstring.
Enjoy, and Listen to more bluegrass