What would Rousseau have made of the modern-day balls and chains with which we shackle ourselves? They are not made of steel or iron, but of silicon and plastic and digits and electrons and waves zooming through the air. These are the chains of all kinds of devices, like the BlackBerry, the iPhone and the Voyager. These are the chains with which we have bound ourselves, losing much of our solitude and our ability to see the world around and inside us.