If you're an iPhone user: Happy Upgrade Day! Apple's latest and most advanced operating system, iOS 6, is available to download for free.

The upgrade is available as an over the air update by going to settings > general > software update, or via iTunes. iOS 6 features lots of upgrades like Facebook integration, a completely redesigned Maps app, a smarter Siri, shared photo streams, and the new Passbook app that turns your iPhone into your wallet.

All of the features, and compatible devices are listed on the Apple iOS 6 site.

The upgrade can be a bit sluggish at first as the mad dash ensues to update, so sometimes it's better to wait until a little later today, or even tomorrow. Happy Upgrade Day!