But now that's changed. A new version of the Google Maps for Android app includes the option of downloading maps of up to six areas before setting out. That's especially useful if you'd rather use your cheap home bandwidth rather than the expensive mobile kind, or if you're staying in a hotel with free Wi-Fi.
In iTWire's initial testing, the maximum map size appeared to be around 60MB, which was enough to cover the whole of metropolitan Melbourne from Sunbury to Philip Island and from Werribee to Warburton. The map data downloaded very slowly, but that could be due to heavy load on Google's servers following the announcement.
The new version of the free app is available from Google Play.