I use a GPS app on my iPhone called NavFree - it actually lets you use Google search for geocoding, and then OpenStreetMap data (stored offline, which is awesom

I use a GPS app on my iPhone called NavFree - it actually lets you use Google search for geocoding, and then OpenStreetMap data (stored offline, which is awesome) for the navigation. It works really well. Sadly they haven't updated the data on the Australian version in six months though.