banjo tuning for guitar

I have been playing around lately with banjo tuning on my guitar. It is tuned open G but this is how I have it set up:

The low E string got replaced with an extra high E i had laying around, that makes the 5th string on the banjo.

From bottom going up I have the strings
D (whole note lower than the normal tuning for this string)
B (same as standard tuning)
G (again, same as normal)
D (again)
G (whole note lower than normal)
G (this is a thin string and tuned high)

That means it is tuned like a banjo, but because of the extra sting on the guitar it has 2 "5th" strings.

By putting the two G's one octave apart beside each other you get a neat drone sound. It sounds really Celtic, when you hit both the strings together in a roll.

Who else does this or something similar? Any other neat tricks to do with it? songs that sound good with it?
I already tried using a slide...it didnt work so well.

If you have a bang-around guitar and an extra string laying around I recommend trying it. If you dont know any banjo rolls just look them up online, pretty easy to find. But remember it wont work unless you change the strings around.

I can explain better if anybody wants me too.
-A-