Quick, find that elusive white cable and plug in your iPhone or iPod touch because iOS 4.1 has gone live via iTunes.

The new OS was announced at Apple's Special Event on 1 September and brings with it a number of new features. 

You can expect to get Game Center; Apple's new social gaming offering that lets you find friends or play against other people, as well as Ping; Apple's social music sharing offering.

You'll also now have the ability to take HDR photos if your model has a camera and, if you're rocking an iPhone 4, you'll also now be able to upload HD video to YouTube and MobileMe directly from your handset.

iOS 4.1 works with the iPhone 3G, the iPhone 3GS, and the new iPhone 4 - and is a free upgrade.

Those changes in full:

This update contains improvements, including the following:

• Game Center

 - Send and receive friend requests

 - Invite friends to multi-player games over the Internet

 - Play multi-player games by auto-matching with other players

 - View Leaderboards and Achievements

 - Discover new games from friends

• High dynamic range (HDR) photos on iPhone 4

• Support for TV programme rentals on iTunes

• Ability to upload HD videos to YouTube and MobileMe over Wi-Fi on iPhone 4

• Additional support for AVRCP-supported accessories, including next & previous track control

• FaceTime calling directly from Favourites

• Bug fixes, including:

  - iPhone 4 proximity sensor performance

  - iPhone 3G performance

  - Nike+iPod fixes

  - Bluetooth improvements

Be sure to check out our comprehensive guide to iOS 4.1 and while you're at it, you may as well take a look at what to expect with iOS 4.2 as well.