Homographies, the latest work by Rafael Lozano-Hemmer (shown above at Sydney Biennale 2006, Art Gallery of New South Wales) features networked light fixtures (with each other and seven computerized surveillance systems) to choreograph their movements in response to people moving through the space underneath:

In Homographies the “vanishing point” is not architectural, but rather connective, i.e. it is determined by who is there at any given time and varies accordingly. This gives a reconfigurable light-space that is based on flow, on motion, on lines of sight

The work is fascinating but seems a little futile to me as it does not illuminate the space any differently when it moves (surely a requesite of designed lighting?). Rafael Lozano-Hemmer is particularily well known for large scale urban projections such as Body Movies and 1000 platitudes.