A solid sphere split into two halves, joined by a pin. Make a globe. Make a moon. Make a... ball? Use it as a test print. My son wanted a nice smooth round sphere so here it is.

Configurable radius with Thingiverse Customizer.

NOTE: Because of the rounded tops and flat bottoms, these models can be hard to remove from the build plate.

The pictured sphere was made on a Replicator 2 with MakerWare with a 0.2mm layer height, 1 shell, and 25% infill. The STL file was generated from the scode with a sphere radius of 20mm.

It was very hard to remove from the build plate, being round with a lot of bottom surface area, so be sure to use tape or pretreat the plate appropriately.