A week or so after first encountering a Kinect, with its combination of gesture and voice recognition, my little boy was using a restaurant toilet with a touch-free flush, and after realising that it had flushed itself in response to his standing up, he turned round and said "toilet: flush!" to see if it also had voice control.<p>My son - admittedly the child of geeks, so maybe a little ahead of the curve - is growing up in a world where screens have always responded to touch; where devices can usually react to being tilted or moved; where you can control things through speaking, or gesturing.