Time has led to location for a few centuries now. After all, it was theinvention of chronometers that made the critical longitude calculation possible for explorers. Circum-navigation depends on it. In our modern era, the Global Positioning System again turns time into location. Time rains down from the heavens and sophisticated algorithms triangulate differential timing signals into x and y, longitude and latitude.
This is a one way street though. Time turns into location but location in circum-navigation or in GPS stays singular. The receiver knows its location and only its location. This is useful, but not as useful as a two way street. In the first Gulf War, GPS was a critical military advantage. Special ops knew where they were to the foot, aircraft knew where they were as well, but the difficulty was sharing that knowledge and preventing friendly fire. Location aggregation depends on another system.
We are currently seeing the gradual coalescence of location spilling over from the military into everyday life. Time turns into a location and location can now transmit into cellular, Wi-fi, Wimax where it collects into aggregate positions. This is where GIS turns up as the ideal technology for interfacing to these aggregate locations. Location aggregates are merely a trickle for now, a few fleets here and there. However, cell phone GPS will change this trickle into a flood. It is only a matter of time before insurance companies realize a cost advantage in aggregate location and push GPS into all vehicles. Theft and litigation are the cost drivers.
In this future scenario, continuous location for every vehicle feeds into real time routing to avoid traffic congestion and theoretically spreads traffic in ideal meshes, a Nash equilibrium of vehicles. Location can permeate further than vehicular location. Cell phones are intrinsically personal, so global location adheres to individuals. But, drive GPS down into the RFID world and global location adheres to just about anything.
Aggregate locations and GIS interfaces are here, but we are also seeing a big change in distribution. Time to location, location to GIS aggregators, and finally aggregation distribution through the internet closes the loop. All players can know location for all otherplayers. OGC web services are key to the last leg of the loop.