Originally Posted by
sstorkel
chrisch: you may want to consider using the new "geofencing" APIs on CLLocationManager. Specifically: startMonitoringForRegion:desiredAccuracy: or startMonitoringForRegion:. The idea would be to setup a geofence around the user's current location with a radius of, say, 5 miles. When the user goes outside that radius your app delegate gets a notification (via locationManager:didExitRegion:) and you could then record their new position and setup a new geofence around their present position.
Wouldn't that be just as battery intensive? In order for the phone react to a change in location, it has to constantly monitor your location. I seem to remember battery longevity issues reported with people using geofencing on Apple's reminders app, but maybe I'm remembering that wrong.