Hasta La Gadget!

Apple on Monday quietly rolled out the latest version of its mobile operating system, iOS 4 (formerly named iPhone OS 4). The upgrade introduces several key features such as multitasking, a unified inbox for e-mail and the ability to group apps into folders.

The new elements of iOS 4 have been covered thoroughly by Apple and here at Wired.com, so there isn’t much to add. (If you want a nice deep dive, check out Jacqui Cheng’s review of iOS 4 at ArsTechnica.) But we can tell you the new update runs considerably smoother and faster than iPhone OS 3, and overall it’s a fantastic free update.

Will it work on your iDevice? Here’s what you need to know:

iPhone owners

• Original iPhones (2007) cannot run iOS 4 at all. That means you won’t be able to run any apps developed for iOS 4. Bummer.
• iPhone 3G (2008) owners can run iOS 4, but multitasking is not supported.
• iPhone 3GS (2009) and the upcoming iPhone 4 are fully compatible with iOS 4.

iPod Touch owners

• Original iPod Touch (2007) devices cannot run iOS 4.
• Second-generation iPod Touch (2008) devices can run iOS 4, but multitasking is not supported.
• Third-generation iPod Touch (2009 and current) devices fully support iOS4.

iPad owners

• You won’t get iOS 4 until fall.

Ready to go? Here’s how to install the update:

1. Upgrade your iTunes version to 9.2.

2. We recommend you back up your data before running the install, so plug in your iOS device via USB and hit Sync.

3.  When you’re done syncing, click Check for Update.

4. Download iOS 4, then follow the on-screen instructions to install. And you’re done!

Photo: Jon Snyder/Wired.com