Last weekend I got a flight to Auckland and from there we rented a car to drive to Warkworth for the Foo Camp.
While the drive is quite easy, some roadworks meant a detour - and we used Google Maps for Windows Mobile with no problem. It only really lacked the voice instructions but everything else was very accurate.
I've been using google maps 1.0 for PDA beta, and suggest it's well worth a try, however not anywhere near a replacement for the navman like options as it doesn't have the directional arrows & voice. Those people at Google are very clever!
Directions are none the less very good and with a GPS it's mapping it's spot on. Great for finding an address and working out where you are, no need for a map book anymore...
Without GPS it works out your location to 1700 meters which is quite impressive. Believe it triangulates your location..