This robot uses the simple change of brightness of a single area of a screen that is being monitored by a NXT LEGO sensor to communicate the intended travel direction.
“This robot demonstrates iPhone to Lego Robotics communication via the Safari web browser and the Lego NXT Light Sensor. To build this, you’ll need a laptop, two iPhones, and a Lego NXT Robotics Kit. First, build your robot. Second write some Java LeJOS Robot code. Third write some Google Web Toolkit web application code. Fourth, plug in your iPhone into the robot, and use either a browser or another iPhone to drive the Lego Robot!”