Graffiti enables users to draw on walls using a mobile device. It includes an iPhone application and a desktop client to capture an on-screen drawing and output it through a digital projector. The idea being that any surface can become a drawing surface. I wanted to see what it might be like to draw on a large scale, and to see how a simple line drawing might be included in a natural setting. The iPhone screen is small and makes precise drawings difficult. I wondered how this might inform the process of drawing, taking small finger gestures and throwing them on to a larger canvas. The projector is mounted in the back of a car, so the system is mobile, allowing drawing to take place in any environment.