Amazing performance art

This is built using Processing.

Messa di Voce (Performance), Excerpts from Tmema on Vimeo.

Presence [a.k.a Soft & Silky]

Fantastic example of motion/touch technology

presence [a.k.a soft & silky] from smallfly on Vimeo.

Field.io Projects

Outdoor interactive installation - More info here

Bright Nights, NYC '06 from FIELD on Vimeo.

The Science of spying - Interactive museum piece using motion detection

The Science Of Spying: Escape from FIELD on Vimeo.

The Orbiter - Interactive sound environment. No video but good graphics and information.

Flash Actionscript 3 motion tracking

Very good site with Flash motion detection includes source code and a good video with demonstration of how it could be used.
http://blog.soulwire.co.uk/flash/actionscript-3/webcam-motion-detection-tracking/

Here's some other sites with cool tutorials or ideas about motions tracking within flash. (Webcam needed for some of them)

Face detection
http://www.marcpelland.com/2009/03/16/face-detection-opencv-in-as3/

Hall of mirrors type webcam effect
http://www.spikything.com/blog/index.php/2009/06/23/webcam-spherize/

Move a 3d cube using motion
http://labs.grinant.com/

Motion detection head a football
http://www.urdalen.com/blog/?p=214

Kef Muon – sound reactive installation

Kef Muon – sound reactive installation from Moving Brands on Vimeo.

Fiat - Interactive Installation

Fiat – interactive installation at concept store from Moving Brands on Vimeo.

You move you interact Project

Microsoft Surface - The Possibilities

Autodesk Design on Jeff Han's Perceptive Pixel Multi-Touch

Interactive Floor and Interactive Wall

Sudden Motion Sensor Game