iPhones secretly track your movements. For a quick travelogue of your favorite places, open the Settings application and navigate to Privacy, Location Services, System Services, and finally Frequent Locations. Here, you'll find a list of your favorite hot spots, complete with times for when you arrived and left. Apple tracks this information to help predict travel times, such as how long it actually takes to get home from work. If this creeps you out, you can turn off the feature from the same menu.