iOS 4.2: What you need to know

Macworld - If you cast your mind back to high school physics, you might recall what's dubbed the Grand Unified Theory -- an attempt to explain how three of the primary forces of the universe were once a single, unified force. So you might call iOS 4.2 the "grand unification" release of iOS, as it at long last brings the iPad, the iPhone, and iPod touch under the same roof.

While we ran down iOS 4.2's key features back when it was in beta, you might still find yourself with questions. Read on for the skinny on the latest update to Apple's mobile OS and check out our lists of ten great features in iOS 4.2 and ten features that we're still waiting for.

Okay, okay, what's the big deal with iOS 4.2?

Most prominently, iOS 4.2 finally brings the capabilities of iOS 4--multitasking, folders, and more--to the iPad. But it also brings two new big features of its own: AirPlay, which lets you stream media from your iOS device to your Apple TV or third-party equipment, and AirPrint, which lets you print directly from your iOS device to certain compatible printers. And just for good measure, there are a handful of smaller improvements along for the ride.

So, I can finally print from my iPad?

Well, that depends. While Apple originally touted the ability for iOS devices to take advantage of printers shared from a Mac or PC, it looks like that feature didn't make the cut for Mac OS X 10.6.5. So instead you'll need to have a compatible HP eSmart printer. There's still a chance that printer sharing might return at some point in the future, but Apple hasn't exactly been forthcoming about when--or if--that might happen. In the meantime, check out our detailed piece on what AirPrint can do for you today.

But at least I can stream media from my iOS device, right?

Again, the answer is a qualified yes. If you've got one of Apple's fancy new Apple TVs, you're all set--you can stream pictures, audio, and video from any supported app--which includes the built-in iPod, Music, Videos, iTunes, and YouTube apps--at will. AirPort Express owners can only stream audio from iOS devices. In addition, third parties such as Bowers & Wilkins, Denon, Marantz, JBL, and iHome have already announced their intentions to build AirPlay-compatible speakers and receivers and, in some cases, provide firmware updates for existing units. Take a look at our overview of AirPlay's capabilities for more.

What if I don't have a fancy printer or A/V gadget? What's in 4.2 for me?

If you're an iPad user, then multitasking is undeniably the big draw. Even then, though, you'll need to wait until app makers update their software to take advantage of the new features. The good news? Many programs that run on both the iPad and iPhone already have multitasking support built in. You'll also get the other 4.0 features.

Remind me what those are again?

Mail now has a unified inbox that lets you see all your new messages in one place, and it can organize messages by thread. Folders let you group applications and help reduce Home screen clutter--the iPad lets you fill a folder with up to 20 different apps. And there's Game Center, Apple's gaming social network, which lets you compare scores with your friends, rank in leaderboards, and earn achievements in supported games. Round it out with support for iTunes TV show rentals and the Ping social networking service, and it's nothing to sneeze at.

I've got an iPhone or iPod touch -- what do I get out of 4.2?

Besides AirPrint and AirPlay, iPhone users mainly get a handful of smaller features at their disposal. For example, you can now search for text on a Web page, control VoiceOver from a wireless keyboard, and take advantage of the expanded international support that adds keyboards and dictionaries for languages like Arabic, Greek, and Hebrew.

Surely there's more in this update.

That's not really a question -- and don't call me Shirley. But, yes, there are plenty of smaller features too. For example, iOS 4.2 expands the available tones for when you get a text message and lets you change the font for the Notes app (under Settings -> Notes). Parental controls now allows parents to restrict kids from deleting apps as well as installing them, changing account information, and playing multiplayer games or adding friends in Game Center. You can also now choose to have the hardware buttons not change the alert or ringer volume along with the volume of media you're playing back, a welcome fix for many who have accidentally quieted their alarms.

Fine, you've convinced me. How do I get this magical update?

As always, just plug your iOS device into iTunes -- if you're not prompted, click Check for Updates and away you go. Remember to sync your device first so you get a full backup, just in case.

Originally published on www.macworld.com. Click here to read the original story.