I have a speaker project that requires some spherical enclosures. After much searching, it seems that short of casting out of concrete, the best way to make the finished product would be to buy two wooden bowls from IKEA and glue them together. That said, IKEA products are not used for speaker building for a variety of reasons, including resonance, appearance, cost, and the fact that I'd have to drive all the way to Chicago to get them.
Anywho, I'm wondering how much it would cost to have some spheres (specifically, four more-or-less identical hemispheres) turned on a lathe. By stacking rings of decreasing diameter on top of each other I can approximate the shape of a sphere pretty well, but I'd need someone with a lathe to make them properly round. Exact precision isn't that important, but they do have to appear identical to the naked eye.