Enable Google Contact Sync Without an iPhone or iPod Touch

An interesting article http://lifehacker.com/393855/enable-google-contact-sync-without-an-iphone-or-ipod-touch

Open up ~/Library/Preferences/com.apple.iPod.plist and save a backup copy of it. Then, expand the tree to reveal "Family ID." Change that value from 10000 to 10001.
Save your changes. Launch Address Book and open the Preference pane. The Google contact sync option will be staring right at you.