My second acoustic is also currently set to DADGAD as I am trying out a few songs in that tuning.
I have also experimented with Nashville tuning where you replace the wound strings with lighter gauge strings tuned an octave higher. This is really to play alongside a normally tuned guitar and gives a pseudo 12 string sound when both guitars play simultaneously which sounds great live or for recording.
A band I played in used to do The Rain Song and I used a Variax with a preset I made for the tuning - D G C G C D.
Love the song and tuning but I don't know of any other song that uses it!