We recently worked on a mapping application that lets users monitor their driving habits using real time data from their cars. The data came in the form of latitude/longitude points, from which we would build a trip and calculate statistics for that trip (speeding, distance, etc).

Because the car sends lat/long data every second, a Trip object can contain thousands of points. Each of these points in turn stores the standard rails timestamps, the latitude and longitude themselves, and some relational keys.