I really appreciate well-produced synchronization, because I’ve experienced firsthand how difficult it is to get right. It seems that software developers can never quite agree on how to organize contact information, so everyone’s databases are different. For a long time, for instance, one of the major makers of financial management software didn’t even create city, state and ZIP/postal code fields, opting instead for an address field where all of that information was run together, making the data very difficult to parse.

So I’ve been pleasantly surprised with Snow Leopard’s “sync with Google” function, especially because I have a fairly large address book, and most of its entries have photos associated with them, something that very few sync solutions even try to support.

With a little planning, you can easily sync your address book with Google. Here are some tips — some of which are also applicable to other synchronization systems, such as the one available for synchronizing data between Google and Thunderbird’s Address Book on a PC.

1. Clean up your contacts. It’s easy to get sloppy about how we enter information, so it’s worth looking through your Address Book to make sure that your data is accurate and well-formatted. Putting first names and middle initials together in the first name field can produce amusing results, as can forgetting to check the “company” box for such entries — I had one card titled “Daily, Web Worker”! I also discovered a bunch of messed-up entries that had apparently been caused by previous experiments with sync software and services. One such service must have been European, because I found lots of entries where the postal code preceded the city, as is standard in France, but which isn’t correct in North America or the UK. Be careful with international phone numbers, too. If you don’t precede country codes with the plus (+) sign, some programs will try to format the numbers in North American format.
2. Back up your data! At the least, use Address Book’s Export function, and save a backup in Address Book Archive format. If you want added safety, use a program like Address Book to CSV Exporter to save your data in CSV format, which can be read by lots of other programs.
3. If possible, don’t try to sync two sources with different data, at least for an initial synchronization. You’ll get best results if you can clean up your data in the Mac Address Book, and completely erase all your contacts in Google. However, if that’s not possible, the charmingly named Conflict Resolver will spring into action during the sync, and give you the choice of which records to keep.

Once you’re ready, enter your account information into Address Book’s Preferences. Go to Accounts, check the “Synchronize with Google” option, click “Configure,” and enter your Gmail or Google Apps email address and password. That’s really all there is to it. I’ve found that you need to be logged out of the Google web interface for the sync to start. You might also need to make a change to your Mac Address Book in order for the sync program to become active, but once it begins, the process is surprisingly fast.

The Mac-to-Google sync system does have limitations. It can sync with one Gmail or Google Apps account at a time, and although it offers sync with Yahoo Mail’s contact lists, I’ve never been able to get Yahoo sync to work. Sync is also available with Apple’s MobileMe service, but I haven’t tried that.

All in all, I’m quite pleased with the results, and am happy that I can have immediate access to my contact information in several different places. As far as I’m concerned, one can never have too many backups of this vital data.

How do you keep your contact data synchronized?

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