A method for locating nearby mobile devices, comprising the steps of: a) installing an application in advance on a plurality of mobile devices, wherein said application is adapted to connect via a data network to a remote server; b) uploading, by one or more mobile devices of said plurality of mobile devices in conjunction with said application, to a database in communication with said remote server, a sound signature indicative of an availability status of a corresponding user of the one or more mobile devices of said plurality of mobile devices; c) continuously collecting location data, by said remote server, of each mobile device of said plurality of mobile devices; d) obtaining via said data network, by one mobile device of said plurality of mobile devices which is functioning as an exploring device, in conjunction with the installed application, one or more sound signatures which have been uploaded by one or more mobile devices that are within a predetermined range from said exploring device; wherein step d comprising the steps of: e) extracting from said database, by said remote server, following connection of the application of the exploring device to said remote server, a list of friends of the user of said exploring device; f) extracting from said database, by said remote server, one ore more sound signatures which have been respectively uploaded by one ore more mobile devices that are within a predetermined range from said exploring device and whose corresponding users are friends of the user of said exploring device; g) transmitting, by said remote server, to the application of said exploring device, the extracted one or more sound signatures and the location data of the one or more mobile devices which have uploaded the extracted one or more sound signatures; wherein the method further comprises the steps of: h) communicating with a selected one of the mobile devices whose corresponding users are friends of the user of said exploring device and that are within said predetermined range by activating a talk button displayed on an application-related interface of the exploring device or by recording a voice message by means of said interface, wherein said voice message is sent to said selected mobile device as an audio file by the exploration application installed on said exploring device. a) installing an application in advance on a plurality of mobile devices, wherein said application is adapted to connect via a data network to a remote server; b) uploading, by one or more mobile devices of said plurality of mobile devices in conjunction with said application, to a database in communication with said remote server, a sound signature indicative of an availability status of a corresponding user of the one or more mobile devices of said plurality of mobile devices; c) continuously collecting location data, by said remote server, of each mobile device of said plurality of mobile devices; d) obtaining via said data network, by one mobile device of said plurality of mobile devices which is functioning as an exploring device, in conjunction with the installed application, one or more sound signatures which have been uploaded by one or more mobile devices that are within a predetermined range from said exploring device; e) extracting from said database, by said remote server, following connection of the application of the exploring device to said remote server, a list of friends of the user of said exploring device; f) extracting from said database, by said remote server, one ore more sound signatures which have been respectively uploaded by one ore more mobile devices that are within a predetermined range from said exploring device and whose corresponding users are friends of the user of said exploring device; g) transmitting, by said remote server, to the application of said exploring device, the extracted one or more sound signatures and the location data of the one or more mobile devices which have uploaded the extracted one or more sound signatures;