Calabi-Yau Manifold Crystal, 3D Topologist Porn

Holy Crap! Thats all I can say about this, but if you want to know more I've dug up a few things for you.

Wiki of course

Steve Wolframs Mathworld

and for the even more technically inclined the Calabi-Yau Home page
Also an artist who creates them Bathsheba Grossman