We knew it was coming this week, but Google today switched on Navigation for Android devices in Australia and New Zealand.
The service - which doesn't require you to update the Google Maps application - will work on any Android device running 1.6 or above and running Google Maps for mobile 4.2 or above, which is pretty much every Android handset on the market.
While it doesn't feature complete maps stored on your device, it does cache enough of the information to be able to direct you to your destination should you lose connection - so long as you don't miss a turn. Once you regain your 3G signal though, it'll do its best to get you back on track with voice navigation.
Considering this is a free application, and integrates with Google's voice search perfectly, it's kind of hard to justify spending any money on dedicated navigation software, especially for Android. At this stage it is only for Android, apparently because only Android phones feature the 3D graphics capabilities to support the interface the app uses. Not so sure that the most recent iPhone or any of the Wndows Phone 7 phones wouldn't be capable of the same processing grunt, but if that's the way they want to spin it, more power to them...
Anyway, if you use Android, check it out - it's actually really good!