Apple users who updated to Mountain Lion on their Macbooks were in for a surprise this afternoon.

Shortly after Apple released their new mobile operating system, iOS 6, Apple also quietly put out a new Mountain Lion update. The OS X 10.8.2 update is a 365 MB download.

Even though there hasn't been much of a buzz surrounding the new update, Mountain Lion 10.8.2 has many of the new features we were expecting when we first saw glimpses of Mountain Lion, namely, system wide Facebook integration on your Apple computer.

Just like they did with Twitter, Apple is now making it easier for you to post and share things to your Facebook account. Just sign into your Facebook account in the System Preferences app and you'll see Facebook integrated with almost every app you have, from Safari to your Notification Center.

While Twitter integration was available when Mountain Lion was released, we knew that Facebook integration with your computer would be available in the fall. However, no date was specified, which made this update a great surprise for Apple users.

The Mountain Lion update also has many other features, including a tighter link with iMessage. Now, iMessages sent from your iPhone, iPad, or iPod Touch, now show up in your Messages app on your computer.

Also, there is a new Game Center update as well. Now, its easier to share scores to Facebook, Twitter, Mail, or Messages, and your Facebook friends will be included in Game Center friend recommendations.

There are also smaller, but significant updates, like a new shared Reminders list, the ability to add passes to Passbook (the new iOS6 app) from Safari and Mail, shorter URL's when tweeting from Notification Center, and more.

You can download the 10.8.2 Mountain Lion update for free using the Mac App Store. You must have purchase Mountain Lion in order to update.