1. A method comprising: recording a first location of a mobile device; determining, by one or more processors of a geographic-positioning component of the mobile device, on a periodic basis, a current location of the mobile device; detecting, by the processors of the geographic-positioning component, a current status of the mobile device, the current status comprising: a detected velocity of the mobile device; time of day information; a battery level of the mobile device; and an error of the determined location measurement; calculating, by the processors of the geographic-positioning component, a radius defining a geographic region around the first location, wherein the size of the radius is adjusted from a pre-determined value based on one or more components of the current status; determining, by the processors of the geographic-positioning component, whether the current location is outside the geographic region; and if the current location is outside the geographic region, then sending, by the processors of the geographic-positioning component, a message to one or more other processors of the mobile device, the message causing one or more of the other processors to transition from a sleep state to an active state.