A Berlin office building has become the world's biggest interactive computer display. The upper eight floors of the building have been transformed in to a huge display by arranging lamps behind the building's front windows. A computer controls each of the lamps independently to produce a matrix of 18 by 8 pixels.

During the night, a constantly growing number of animations can be seen. But there is an interactive component as well: you can play the old arcade classic Pong on the building using your mobile phone and you can place your own loveletters on the "screen" as well.

Anyone for tennis?