Motion activated exterior lighting has been promoted for years from both the security and the energy conservation angle, but we recently discovered an indoor gadget that uses room occupancy to trigger lights. These motion sensing light switches have been around for a while but haven't received the press of the energy saving light bulbs. They are also a little hard to find. We located two manufacturers - Cooper Wiring Devices and Leviton. The former is sold at Lowe's but not at all locations...