"Download map" for Android

One way we bring you new product features is through Google Labs—a collection of fun, experimental features you can turn on if you’re interested in the functionality. In fact, Google Maps itself started as a lab. In addition to our desktop Maps Labs, Google Maps for Androidhas a few tricks you can try out right from your phone. We’d like to introduce you to one new experimental feature, “Download map area," but also remind you of two other ones we already have: “Scale bar” and “Measure.”

Download map area
When you’re visiting an unfamiliar location, Google Maps for mobile is great for getting an idea of how close you are to your destination, where streets and landmarks are in relation to each other, or just for getting “un-lost.” But what if you don’t have a data signal, or you’re abroad and don’t have a data plan? We say that if you use Google Maps for mobile, you’ll never need to carry a paper map again. The “Download map area” lab in Google Maps 5.7 for Android is a step in making that statement true even when you’re offline.

Let’s say later you’re visiting Bordeaux during a trip to France. If you were to open Google Maps for mobile and zoom into Bordeaux without data coverage or wifi, you’d see the image on the left:

Left: Bordeaux with no data or wifi. Right: Bordeaux with downloaded map area

That’s not particularly useful when you’re trying to find out how close you are to the Cathedrale St. Andre. But a little advance planning and “Download map area” can help. Before you take your trip, while you still have access to WiFi or data coverage, you can open up any Places page in the world, click “More” to get the Place page menu, and download Google’s maps for a 10-mile radius.

Left: Tap a landmark to enter its Place page. Right: Place page “more options” menu

The download can take as little as a minute or two. This download stores only the base map tiles and the landmarks on the map, so you still need a data connection to see satellite view and 3D buildings, search for Places and get directions. But we hope the level of detail available will help you find your way!

Left: Status screen for download. Right: Coverage of downloaded map area

All your downloaded map areas can be managed in your Google Maps cache settings so you can delete maps you no longer need or if you want to free up storage. After 30 days, all downloaded map areas will be removed from your cache; they can be re-downloaded any time.

Scale bar
Google Maps has approximately 20 different zoom levels that range from a 2,000 mile scale to a 20 foot scale. With finger gestures making it really quick and easy to zoom in and out, sometimes it’s not always clear what zoom level you’re at. What might be just a few streets away can be quite a long walk depending on the scale. To help with this, you can turn on a scale bar, which updates based on your zoom level.

Scale bar in the lower left

Measure
If you ever need to know the distance between San Francisco and New York (about 2602 miles) or between any other two points on the map, the “Measure” lab can help you out. Once it’s enabled, you’ll notice a tape measure icon just above the zoom buttons. After clicking that icon, you’ll be prompted to tap two points on the map and Google Maps will calculate the straight distance between those points (this direct distance is “as the crow flies”).

Example of the “Measure” Labs feature

To access Labs on your phone, press your phone’s menu button once in Google Maps, choose “More” and select Labs. On a tablet, click the menu button in the upper-right corner of Maps. The “Download map area” lab requires Android 2.1+ and the latest version of Google Maps. We look forward to bringing you more experimental features soon and hope you enjoy trying out Labs in Google Maps for Android.

source: http://googleblog.blogspot.com/2011/07/download-map-area-added-to-labs-in.html