Google announced today via their Gmail Blog:
Starting today, we’re adding CardDAV – an open protocol for contacts – to that list. CardDAV enables 3rd party clients, like the iOS contacts app, to sync your Google contacts. By supporting IMAP, CalDAV, and CardDAV together, we’re making it possible for 3rd parties to build a seamless Google Account sync applications.
This is fantastic news for us iOS and Mac OS X users as it will make managing our contacts even easier.
One of my main frustrations in not using a full blown Exchange mail solution was not being able to manage my contacts with my Google Apps for my domain account, but now I can.
Yesterday Google I was questing your motives and today I am praising them. Welcome to technology today.
Update: Check out this how to guide for OS X Lion and Above