Colour by Numbers (images above, video below) is another work which can be controlled through a mobile phone. This time an architectural installation which has had two incarnations at Telefonplan in Stockholm, Sweden in 2006 and the Tower of Perdigones, Seville, Spain in 2008/2009. Its creators see the work as a means for individuals to influence space in the urban landscape through the mediated spaces and forms of technology:

A window full of light has many connotations in the context of a modern city. It can make visible a section of the private sphere, or attract passers-by to public spaces, like department stores, churches or museums. Commercial signs are obvious symbols which are relevant for our tower. The vertical extension is also central. All architecture likes to add its signature to the surroundings with height. The cityscape becomes a kind of mass medium. In this case, this means that a relatively flexible area contacts a broad and diverse public. The mass medium is a physical area, a place where you can write a message. Representational buildings like churches and castles have always been like this. But this tower is an example of architecture that has to negotiate its identity with the surrounding city. Roads, homes and offices are becoming more and more like screens which are made available for different messages. In the general collage, anything can be claimed to add a signature to a place and signal (temporary) presence. Cell phones and the internet are also media that create space. Their public nature both complements and competes with the tower’s spacial visibility. You can control the signals with your phone, and you can see them on location or on the internet. The technology is accessible for the individual. Which is good - the public space should be open to any person or usage that gives others the same freedom.

This is enabled through stylised or symbolic mark making which while enabling the democratic aspects of graffiti is presented in an acceptable manner similar to street advertising:

It can seem obvious that political symbols in the public space have to be strictly regulated. But access to this space is also to a high extent open for pragmatic and economic arguments. Inscriptions on a publicly owned area are judged differently from signs on privately owned areas. A billboard is in a certain sense an area for sending a message in the public space, but the person paying for it controls it. Private citizens rarely get the chance to send their messages high above the houses and subway, as now at Telefonplan. There are other ways for an individual to reach out into the public space. If you don’t have legal or economic access to display windows in the public space, you can of course illegally write your message on their exteriors. This “from the outside” technique, graffiti, is so controversial that its graphical style has been stigmatized and criminalized.

The article Claiming Space (extracts above are from this) about this work is a fascinating read and well worth a look.