Digital Shadows is a tangible interfaces that allows people in different places to create a collaborative shadow puppet show.
Each participant can join using their webcam and simple household objects (paper, fabric, lamps, etc.) in order to generate to the system sketched below.
For a more in depth explanation, take a look at these system details.
The software includes a series of gesture-activated interactions including multiplication, scaling, and mirroring, that allow physical objects to be digitally manipulated as shown in the short clips below.