Blinkenlights is the interactive light installation that allows mobile phone users to create animations or play games such as Tetris, Pong or Pacman on the facade of buildings.
And it is coming back to its original building in Berlin for two weeks.

You can play Pong if you call 0190-987654. The money you pay on the phone is for the project. So you can donate by playing outdated computer games.

you will be able to receive the Blinkenstream via CCC‘s X11 simulator software. Install the blinkensim , select a “hdl” theme, make blinkensim connect to proxy.blinkenlights.de and get the screen’s content streamed over the Internet and play Pong from whereever you want.

Check also the webcam pointing to the installation.
Via Tim in The Lunatic Fringe.