A motion-controlled light switch in an office building in Palo Alto,  California.  If no activity is detected for several minutes and the switch is on, the lights in the room automatically shut off.
<a href="//commons.wikimedia.org/wiki/User:BrokenSphere" title="User:BrokenSphere">BrokenSphere</a>
CC BY-SA 3.0
<span class="int-own-work" lang="en">Own work</span>