There´s a reason you´re such a klutz when lopping off the head of a virtual ogre: You can´t feel what you´re doing. But game players will soon be able to get their hands on virtual-touch technology initially developed by Sandia National Laboratories and once reserved for such costly equipment as surgical simulators used to train medical residents. Novint Technologies´s desktop Falcon controller (novint.com), which will cost about $100, is the first interactive 3-D touch device for the home PC.