A GNSS-based, bidirectional mobile communication system includes a mobile unit, such as a vehicle or a personal mobile system, with GNSS (e.g., GPS) and Internet (worldwide web) access. A base station also has GNSS and Internet access, and provides differential (e.g., DGPS) correctors to the mobile unit via the Internet. The Internet communications link enables audio and/or video (AV) clips to be recorded and played back by the mobile unit based on its GNSS location. The playback function can be triggered by the mobile unit detecting a predetermined GNSS location associated with a particular clip, which can be GNSS position-stamped when recorded. Alternatively, clips can be generated by utilities and loaded by the application either from a personal computer or automatically over the Internet. Moreover, maps, vehicle travel paths and images associated with particular GNSS-defined locations, such as waypoints, can be updated and position-stamped on the data server. A GNSS-based mobile communication method and a storage medium encoded with a machine-readable code for mobile communications are also provided.