The model is a free and open model that comes with Blender (the Blender Foundation has affectionately nicknamed the monkey Suzanne). I wanted to print it, but it could use finer detail and it also has tons of overhangs which are not good for MakerBot just yet. So I modified the design in Blender with SubSurf modifier (setting of 3 to make it much smoother), exported to stl, and then printed the model with symmetry in mind -- print exactly one half of the head, flip one of your axes to print it's mirror image, then glue or epoxy them together.
In Blender or your favorite 3D program, Cut your spherical objects (like a head) in half, bisecting the face top-down (a saggital cut).
Print this first half.
Now you need to print the mirror image. Do it in hardware, not software. It's much easier:
To print the other half as the EXACT mirror image, just edit your hardware settings to flip either your X or Y axis. This will make an exact mirror image object, guaranteed. No re-skeining needed.
I often design mirror image objects, and this saves half the rendering, slicing, and printing time, and saves HD or SD card space too.
Best of all, editing your hardware settings to flip either the X or Y axis means you can print the same .s3g file twice, taking up half the space it normally would to store/process both a left and right object.
I include the .blend file in case you want to take a peek at the subsurf object (it's on layer 10... press the 0 key to go to layer 10 in Blender).