Provided is a critical point method used to determine the points of a real-time stream of location data, such as Global Positioning System data, that should be retained based on their importance in reconstructing the travel path of a mobile device. A first storage unit stores data transmitted from an external apparatus. If the user purchases a prepaid card and loads a balance into a prepaid utilization account, a prepaid services system of the roaming service provider establishes a pseudo-telephone number for use by the wireless telephone in the roaming service area. Methods and systems, as broadly described herein, comprise a message archive containing a plurality of messages, each having a client identifier and an archive token, and permit a requester access to select messages in the message archive based on an identifier for the requester and consistent with rules for archive retrieval.