This is a very short video test with description (pause often!), of a CG texture-independent flat facial rig technique using Blender. It's basically just meshes put really close to each other, with Boolean modifier applied to sell the illusion of eye socket. Everything else is armature and driven-shapekeys.
The demo rig just consists of an eye, but I think covers some crucial techniques applicable in creating these kinds of rig, which are all really simple if you know rigging in Blender. Rig downloadable at http://www.mediafire.com/?fdc6e0nwmkio33d.