"You can download an area by searching for a city, county or country, for instance, and tapping "Download" on the resulting place sheet, or by going to "Offline Areas" in the Google Maps menu and tapping on the '+' button. Once downloaded, Google Maps will move into offline mode automatically when it recognizes you’re in a location with spotty service or no connectivity at all. When a connection is found, it will switch back online so you can easily access the full version of Maps, including live traffic conditions for your current route."
Not only will this come in handy while in remote areas during stressful situations (i.e. the Amazon with leopards, Idaho with lead-foot Earl) if you know you use a certain area frequently, loading the map onto your phone and saving it can save a substantial amount of data and battery life -- as opposed to opening and loading your Google app every time you need it. Or, it could be a viable solution to those boring plane rides, sans WiFi. Nothing is more interesting on a long plane ride than studying the diverse and fruitful neighborhoods of lower Alabama.