From Nate and Glenn

Shadow Sculpture: http://www.instructables.com/id/Shadow-Sculptures!/

Light Patterns: http://www.olafureliasson.net/works/multiple_shadow_house_2.html

LED Throwies: http://graffitiresearchlab.com/projects/led-throwies-ii/

Forced Perspective: http://disneyparks.disney.go.com/blog/2011/04/beast-castle-behind-the-scenes-with-walt-disney-imagineers/