How to make a head

Required 

123D Catch for either PC or iPad

123D for PC

Meshmixer

Makerbot Replicator 

Use a digital camera to take pictures or the iPad within the 123D Catch program

Take ~30 pictures from different angles.  I take them from about 75° to -75° from center.  I have done around 8 at eye level, 8 looking upwards about 30°, 8 looking downwards about 30°, and 3 from about 60°.

If you used a digital camera, load the pictures into 123D Catch and upload them to the 123D internet site.  With the iPad, you can do this from within the application.

After around 15 min, the raw 3D model will come back / be downloadable

You will have to clean up this model before printing.  With the iPad, email the model to a PC which has the program 123D Catch installed.  Open the model in 123D Catch and save it as a .obj file.

Open the .obj file in Meshmixer.

Crop away the background.  Make a flat pedestal for the head.  Save as an .stl file.

Open the .stl file in Replicator G program which controls the Makerbot Replicator.  Center the head and put it flat on the platform.  Adjust the size.  Print. 

Alternatively, you can have a company make it.  Shapeways is a possibility.