The Rain Room by rAndom International is an interactive installation which is also part of the EXPO 1: New York exhibition. The Rain Room is a 100 square metre field of falling water that visitors may walk through and experience how it might feel to control the rain. 10 people can be tracked by the system and everywhere they go, the rain will stop. It’s really a magical experience.
Here’s a video form the Rain Room when it was installed at the Barbican in London.