Take your mobile phone (iPhone or Android, also iPod Touch, iPad or Laptop works) out of your pocket, enter the URL that you find there, and on your screen you will see what's on the LED wall. Then you can paint on that. Of course with the technology of Colorillo, multiple people can draw at the same time.
The resolution is a little limited, as the LED wall had been built by hand by students of architecture, so in my experience it's a little more like splash painting with colors, but we'll see how it turns out tonight.
Tonight (July 22, 2010) at 8:30pm there is a special drawing event with John Megill of FM4 as a DJ. If you're around, come by! It will be fun!
The whole event is hosted by the Ärzte ohne Grenzen (Doctors without borders) beach that has been set up for the duration of the AIDS conference that is being held in Vienna this year.