1. A portable electronic device connected to a server via a network, comprising: an image sensor configured to capture at least one image; an optical output device; a processing device coupled to the optical output device, the processing device being configured to: retrieve geographic information associated with the at least one image; identify, based on the geographic information, at least one contact included in a set of contacts of the portable electronic device, the at least one contact being associated with another portable electronic device connected to the network, the another portable electronic device having captured at least one other image in a geographic area in which the at least one image was captured; and control the optical output device to display on the portable electronic device an identifier for the at least one contact; and a communication interface for wireless communication configured to receive the at least one other image, the communication interface being further configured to receive a notification transmitted by the server when the another portable electronic device captures the at least one other image in the geographical area, wherein the processing device is configured to update the identified at least one contact based on the received notification, and the processing device is configured to control the optical output device to display the at least one other image.