Apple kicked off this week with its first big update to iOS 6 since it was released in September. iOS 6.1 includes several feature updates related to LTE coverage, Siri, iTunes in the cloud, and advertising.

The updates:

• More LTE carrier coverage. CEO Tim Cook announced this was coming on Apple’s earnings call last week.
• Purchase movie tickets via Siri. You could previously search for movie times via Apple’s voice interface, and get showtime results via Fandango — now you can buy tickets in the same interaction.
• iTunes Match subscribers can n download individual songs from iCloud.
• A new button that allows users to reset the Identifier for Advertisers. In iOS 6, Apple tried to wean advertisers off of UDIDs with the new IFA. It also gave users more control over whether their in-app behavior was transmitted to app developers or advertisers.

The update is available via iTunes or over the air update. iOS 6.1 is available for iPhone, iPad and iPod touch users.