Here is a rather half-baked stab at a planar map, based largely on the D&D standard. I'm putting it up not because I love it, but because I love the idea of mapping the planes, which transcend normal spatial conceptions. It's something I'd like to work on more intensely, so I suppose I'm just opening this page up as a precursor of things to come.
I think utilizing a 3d representation is key, but beyond that, I could see this mapping exercise going any number of directions. I would love any suggestions you might have.