Abstract: A device worn or carried by a user includes a subsystem including a processor, memory, wireless communication interface configured for communication over a maximum range between 1 and 10 meters, indicator(s), and electrical power source. The memory stores first profile data characterizing trait(s) of the user and second profile data characterizing interest(s) of the user. The first profile data is communicated by the wireless communication interface to at least one other device located within its maximum range. The processor receives and processes profile data wirelessly communicated from one other device located within the limited range of the wireless interface. The received profile data characterizes a person or group or entity or product or service associated with the other device. The processor processes the received profile data by matching the received profile data and the locally stored second profile data, and controls the at least one indicator based upon such processing.