inspired by this one for maya : vimeo.com/21317049
The compound detects point tension and compression to preserve volume and so create wrincles.
You can use point normals to displace the mesh or two sculpted shapes (morphs, blendshapes) to deform exactly as you want.
The face is really not perfect, the rig was done quickly last Sunday to try my tool, and it is my first face rig on Softimage, it could be better, but you have an idea of what it can do.
I don't forget 3dsmax users, I also have an fStretch 3dsmax prototype, I'm still working on it.