I'd like to share the source for my Giant Floating Robot Head demo!  It's an app that lets you control a 3D robot head by moving your own head, and uses volume to control the robot's mouth.

Demo is available here:



Code is available here:

http://code.google.com/p/hangout-experiments/source/browse/#git%2Fface

Outside of showing off some relatively straightforward three.js, the app also demonstrates the value of smoothing.  The app keeps a 5-frame window of values for tilt/pan/roll and then takes a weighted average of them to choose the face position for that frame.  Key source snippets are here: