MacInTouch: timely news and tips about Apple Macintosh, iTunes, iPhone and more...I don't know of any other solution that can backup or interact with Google Contact Groups. They have a somewhat limited 10 day trial solution -- a bit short for my tastes.
... Mac-Chi released Googaby 1.0, a Google Contacts and Address Book utility for Mac OS X. The software enables you to drag-and-drop contact information from any application that allows selecting text and then parses the data, presents it for review and editing, and stores the approved version in Google Contacts. It can also push new or changed Address Book contacts, including pictures and group memberships, to Google in the background. Other features include backup and restore of Google Contacts and Groups, drag-and-drop between Google accounts, drag-and-drop into spreadsheets, support for executing custom AppleScripts, a hyperlinked Note field, and more. Googaby is $24.95 for Mac OS X 10.4 and up (Universal Binary)."
Note, however, that Googaby doesn't attempt to synchronize Google Contacts with Address Book ...
... In the some of the articles which have been published so far Googaby and “sync” have been mentioned in the same sentence...I'd love true sync between Address Book and Google Contacts, but I think the data models are too different to really do that. This seems plausible.
So I want to be real clear: Googaby is NOT a sync agent nor sync tool!
Googaby PUSHES changes from the Address Book to Google Contacts. Pushes one way and only one way.
If you’re a Mac user then you should store your contact data in Address Book.
Not only are the data elements in Address Book much richer than those of Google Contacts, but by storing your contacts in the Address Book...
I'll give it a cautious try on a secondary Google account where I can do some testing safely. (It's easy to backup and restore the OS X Address Book, there's NO backup for the Gmail Contact/Group collection.)
Update: I've found my first (minor) bug. If you launch Googaby from the first time and don't have a network connection, it hangs instead of displaying an error message or log-in dialog. It should display an error message. I had to kill the process.
Update: I'm missing something. It can see how it does a backup and restore of Google Contacts, though I've not tested that. I can also see how it might work to better manage one's Google Contacts, and have them available offline -- but since Googleby is the "source of truth" then any Google Contact changes made, say, by Google Sync to the iPhone will get lost. I also don't see how one creates a relationship between an Address Book entry and a Googleby entry. I see a lot of complexity in the Preferences settings. There's nothing much in the Help files. Googleby looks interesting, but it shouldn't have been launched without a manual of some kind.