iPhone OS 4: Multitasking, finally

The latest version of the iPhone's software will give you 100 new features, including the much-wanted multitasking. Steve Jobs, looking more like Montgomery Burns with every announcement ("Schiller! Unleash the hounds."), launched iPhone OS 4 at an event at Apple's headquarters in California this evening. Launched this summer on iPhone 3GS and third-gen iPod touch, it'll come to the iPad in the autumn.

Yay multitasking! Or is it..?

Jobs touted a better way of doing multitasking than the iPhone's competitors. "It's easy to do this in a way that drains battery life, and a way that reduces performance of the foreground app. If you don't do it right, your phone will feel sluggish," he said. "We figured out how to implement multitasking for third party apps and avoid those things. So that's what took so long."

In fact, the way it works is more like alt-tab switching. You double-tap the home key to bring up a list of the apps you're using, which exist in a kind of stasis. The iPhone wakes up the app you want, which has remembered where you were. Certain functions can be developed with the new API to continue running, such as music playing through Spotify while you're surfing the Web. It also means you don't have to unlock the phone to access functions such as music controls, just press the home button once.

A version will be available for all iPhones and iPod touches, but multitasking and some other features will not run on anything but the latest iPhones and touches. It wasn't announced whether the update will cost you anything, as it has in the past for some devices.

Game Center puts the willies up console makers

As for other new features, Game Center is an Xbox Live for the iPhone. It'll add achievements, leaderboards and match-making to iPhone and iPad games. We've only seen a list of features, but it already makes Nintendo and Sony's efforts in this area look prehistoric. Whether it's as compelling as Microsoft's integration between Xbox Live and Windows Phone 7 will be interesting to see.

iAd: A whole new way of annoying you

iAd is a new advertising system for apps where Apple sells ads that include interactive elements and video, without taking you out of the app. They're easy for developers to include and Apple will take 40 per cent of the revenue. So expect to see a lot more ads in your apps from this summer. "It's all industry standard," said Jobs. "It's all HTML5." Sure, that's the industry standard for ads, Steve. Any plans to add Flash or Java? "No," he said, his voice flatter than the salt pans of Utah.

And everything else...

Background location notification will use mobile phone masts instead of battery-hungry GPS. So if you've got something running that needs to know where you are, such as Foursquare, it'll use the less precise method of bouncing signals off the nearest towers. Like the restrictions on what developers can do in the background, it's a tradeoff between opening up more features and keeping the user experience as seamless as possible.

You'll be able to change the background wallpaper, and group similar apps such as games into a folder, so it only takes up one space on your home screen. This means you can have over 2,000 apps on your phone instead of the 180 today.

Email got some useful upgrades too. A unified inbox means all your accounts pour into one place. You'll be able to organise email by threads too.

It was just a developer preview today, with the update reaching your iPhone this summer. Other features announced included Bluetooth keyboards, spell check, gift apps, tap-to-focus video, places in photos, Web search from suggestions, larger fonts for mail, texts and alerts, rotate photos, sync IMAP notes, iPod out, and wake-on wireless. iBooks will be on the iPhone, but as it isn't even included on the iPad launch page in the UK, it's not that likely that the book store will be here in time for OS 4.

Jobs also announced that Apple has sold 450,000 iPads. iPad owners have downloaded a mighty impressive 600,000 books and 3.5 million apps, from a choice of 3,500 built specially for the tablet. The App Store in total has delivered a whopping 4 billion apps.

What do you think of Apple's take on multitasking? Were there any features you were hoping for? Will Game Center kill off the the DS and PSP? Let us know in the comments below.