Fabricating / Molding / Carving spheres

Fabricating / Molding / Carving spheres
on a tangent of a tangent I poked around for some techniques for producing spheres, and found:

Lapidary Digest - Sphere Making

and a google groups search in rec.crafts.metalworking for sphere that turned up some interesting ideas

and another pass at the same problem in rec.woodworking