1. A tracking system comprising: a tracking device having an on-board power source, a central processing unit, a cellular telephony transmitter and receiver, a speaker and a microphone, a bus system interconnecting electronic elements, and software or firmware executing at least periodically from a machine-readable physical medium to provide a range of functions for the device; a central server in the Internet network having connection through an appropriate gateway to a cellular network having a plurality of cell towers spread over a geographic region; and an interactive interface at the central server providing access to server functions for individuals operating Internet-connected computerized appliances including at least device tracking activity; wherein the device has an ID associated with a particular person, the ID is registered with the server, and the device communicates periodically with the cellular network, providing information including at least location and time for the device, and the server is enabled to gather information of scheduled activities of transportation companies and determine at least geographic position, acceleration, speed and direction information for the device by using successive locations and times received via at least a portion of the plurality of cell towers, all information used by the server to determine a type of vehicle carrying the device, probable destination for the device and schedules future tracking activity for the device based on the determination, making the tracking activity and the information accessible via the interactive interface for the particular person with the associated ID.