US Patent 8144015 Power efficient object detection with selective polling

Detecting the absence of tagged objects near a computing device and attempting to locate the absent, tagged objects using other computing devices in a power-efficient manner. The computing device is monitored for triggering conditions. Upon occurrence of at least one of the triggering conditions, the computing device polls for the tagged objects expected to be proximate to the computing device. By polling responsive to occurrence of the triggering conditions, power consumption by the computing device is reduced. The triggering conditions include, for example, time-based transitions, movement of the computing device, or a geographic location of the computing device. Upon detecting the absence of at least one of the objects, the computing device, or a web service, identifies other computing devices to which the absent object may be proximate. The other computing devices determine whether the absent object is proximate, and notify the computing device.