Pre-caching Offline Map Areas in Mobile Maps

Up until recently, mobile map services required the devices connect to a carrier data network or WiFi. This causes inconvenience for people use WiFi only, because in many cases people need to use the map services under no WiFi connection circumstance.

Recently Google Maps for Android added the map area pre-caching as a Labs feature. Here is how to it works:
First go to Google Maps Settings / Labs and check the “Pre-cache map area”:

Then long press at a point on the map as the cached map area center, and press at the address search result box of the position, you will see the pop-up dialog on the left side of the screen displays the operation options, at the bottom you can see the “Pre-cache map area”:

Select the “Pre-cache map area”, you can see Google Maps starts caching a 10 miles x 10 miles tile centered at the position you just specified:

After the caching is done, Google Maps shows the area it has just cached:

Among other mobile map products, although we have not seen Microsoft Bing Maps publicly announces it supports offline map caching, based on our testing, Bing Maps for Metro automatically caches map areas up to the detailed levels on the device’s persistent internal storage. We will discuss this in details in the future.

Update (2012-06-28):
In the latest update, Google Maps graduates the "Precache Map Areas" feature from the Labs and makes it a generally available product feature, which can be started from the Settings option "Make available offline":