The caching of offline google maps works great, it's now an official feature of the android google maps. However even if I save my caches in a list for offline caching and hit the button 'view in external map' google maps still requires a running internet connection to resolve the coordinates or whatever is handed over by the Groundspeak geocaching app.
I'm really looking forward to a reasonable offline-mode in the offizcial Groundspeak gc app as this has already been possible for ages in the iOS version on my first iPhone 3G ;-(