Gorilla head:

It took a while, but we opted to modify an existing facial rig "the xsi Guy". Tom altered the polygons to make it look like a gorilla's face and then added robotic pieces around the edges.
This saved us alot of time and sped up production slightly. It mainly saved time in rigging all the sliders for the facial expression. The original model came with a great range of expressions, most of which have been kept intact after the modification.