Juan Pablo Bouza has published BlenRig, a humanoid rig for Blender 2.43 based on bones deformation. The rig, which uses over 680 bones and includes full facial animation, comes with a whopping 26 page manual.
Juan Pablo writes:
The main purpose of this project is to make a rig that is Â´shapekey freeÂ´. IÂ´ve developed a somewhat complex skeleton system based on different types of constraints in order to achieve realistic deformation even in the most extreme poses. In addition to this, BlenRig comes with a complete facial animation system rig.
BlenRig is published under a Creative Commons Attribution-No Derivative Works 3.0 License.