This tool streamlines the process of creating deformable controls that were demonstrated by Pixar in one of their demos. It should work for pretty much any rig.
You can download the file here:
It's a technique I learned from Wasim Khan (http://creaturerigs.com/). Check out his stuff, he's a crazy awesome TD!
Harry Houghton had also made a video tutorial outlining the process (vimeo.com/94663329)
The rig is called Morpheus and was created by Josh Burton(http://www.joshburton.com/projects/morpheus.asp)