A system for providing location information to a mobile calling unit operating within or among a plurality of communication networks includes at least one communication access unit for each respective network of the plurality of communication networks. The calling unit effects communications with a respective communication network of the plurality of communicate networks via a respective communication access unit of the at least one communication access unit. The respective communication network and the respective communication access unit cooperate to automatically effect providing at least one almanac entry to the calling unit substantially on occurrence of a predetermined event. The at least one almanac entry relates to geographic location of the calling unit while the calling unit effects the communications.