1. An information synchronization system, comprising: a plurality of mobile terminals, each of the mobile terminals adapted to store telephone number data organized in a group and to transmit the group to a mobile service interface, wherein the group in at least one of the mobile terminals is missing telephone number data that is in the group of at least one of the other mobile terminals; at least one mobile service interface adapted to receive the telephone number data groups from each of the mobile terminals, to combine the telephone number data and to transmit the combined telephone number data for processing; and at least one processor adapted to receive the combined telephone number data, to arrange the combined telephone number data for each of the mobile terminals to include only the telephone number data that is missing from the group for each of the respective mobile terminals, and to transmit the arranged telephone number data to each of the mobile terminals by way of said at least one mobile service interface, wherein, each of the mobile terminals is adapted to store the arranged telephone number data in the group, when the arranged telephone number data is stored in the group of each of the mobile terminals, the group in all of the mobile terminals is synchronized without duplication of telephone number data in the group in any of the mobile terminals, each of said plurality of mobile terminals and said at least one processor are capable of long message service (LMS) messaging with said at least one mobile service interface, and said at least one mobile service interface is a long message service center (LMSC).