Following up on the Maps announcement a few weeks ago, Google has released the long-awaited update for Android which will enable offline caching. That means you'll be able to keep navigating when you're outside of data coverage for whatever reason. Over 150 countries are supported, and you can store up to six large metropolitan areas (like New York, London, or Paris) using the new menu option. Bundled with this update are a few performance optimizations for compass mode in Street View.
Offline caching in Google Maps is going to be particularly awesome for frequent travelers that don't want to get nailed with harsh roaming fees and can't get their hands on a local SIM card. It also makes Wi-Fi-only Android devices viable for navigation, which was never much of an option before.
Source: Google Lat-Long