Digital Water Pavilion
Just opened at the Zaragoza World Expo in Spain, the digital water pavilion is an experimental building with walls made of water. The cascading sheets are programmable and can display different patterns and even words. Walls can react dynamically to input from sensors, spontaneously creating doors when you approach the building. A team from MIT designed the pavilion, and won Time Magazines best invention of the year in 2007.
[via Core 77]