Developed from low-cost sensors, LEDs and light transmitting materials, the IRUS prototype delivers a basic interactive interface to the users of public space; lighting pedestrian movement in real time, without wasting energy and emanating extensive light pollution when no one is present.  Illumination and sound are generated by the device in specific response to streetscape movement and proximity data collected from its visual and auditory sensors.  This single prototype is conceived as a simple node of a larger, complex and interactive network. In aggregate, communication between multiple nodes can produce a sophisticated, tunable, emergent response to human activity.