Smart Dust and Virtual Keyboards

Using Smart Dust which is sprinkled onto a rock it maybe possible to type information into a small computer or PDA very rapidly. This could be quite handy for many things such as; Search and Rescue, Fire Fighting, Civil Air Patrol, Hikers and Mountain Climbers and of course military applications. Think for a second the possibilities for Net Centric Warfare for Special Forces Troops. But how exactly can all this work? Well, simple really, you find a flat rock and spinkle your micro-electro-mechanical