I saw this a couple days back but forgot to update.
Water Light Graffiti is an installation designed by Antonin Fourneau & Digitalarti Artlab, which was set up in Poitiers, France. Antonin has designed a surface which is embedded with LED’s that light up upon contact with water. Splash water onto the surface with the help of any damp object such as a spray, wet hands, wet brush or even a bucket and watch the moisture sensitive surface light up!
It looks like so much fun, check out the images and video below.