Director's commentary for The Fountain online
One would hope that the Director's Commentary for The Fountain would have actually been on the DVD, and while it seems that Darren Aronofsky was keen to do it, Warner Brothers weren't, perhaps they'd written off the film already.
So, as Director's seem to be thinking of doing more and more, he made his own Audio Commentary track and put it on his website for you to download.
On his website, Darren Aronofsky is allowing anyone to visit and listen to The Fountain commentary alongside the DVD, and while he doesn't give away any major answers, he does have a few pointers to help you on your way to your own discovery of the film.
I really like this idea of offering audio commentaries out with the DVD itself, even if there is one offered with the DVD, I'm sure there's much more to be said that could perhaps be talked about outside of studio control.
Even then, imagine anyone involved in the film just putting up their own commentary. Or what would be better is if a collaborative audio commentary software was created, one that acted like a wiki where clips could be placed anywhere along the timeline of the track and layered upon each other. As you're watching the scene you were shown a list of the available commentary clips from different cast and crew on the project and you could select who to listen to for that scene.