Friedrich Kirchner is developing since 2009 an amazing open-source 3D real-time animation tool for easy sketching.
Instead of the standard modeling process, the user just draws the objects or characters in the canvas or scan them from a Microsoft Kinect obtaining a very peculiar expression.
By presenting a node-based system the user can map interfaces for live performances or trigger sequences.
This is a great tool for creatives that can be used in many scenarios, like digital puppetry or even to build presentations.
Movie Sandbox site: http://www.moviesandbox.net
Movie Sandbox digital puppetry example using arduino to connect to a real sock interface
Another great example from 2008 is the manipulation of a virtual marionette using GameTrak and Wiimote