After a long wait, Apple finally unveiled the iPhone OS 4.0 at the "peek into the future of iPhone OS" event with the key feature that many have been craving for-multitasking. Steve Jobs explained that the Apple development team have come up with methods on the multitasking implementation without comprising the OS performance and battery life. (Note: This multitasking feature will not be available for devices older than the iPhone 3GS and iPod Touch third generation due to hardware limitations).

As reported by Engadget, users can now switch between apps by simply double clicking the home button. To make sure the multitasking ability works perfectly, there are seven services apps running in the background, which includes VoIP, background audio, push notifications, navigation and location-based services, fast apps switching.

Some other new features that users would love are:

• App folders for sorting apps (drag and drop features)
• Spell checking function
• Bluetooth keyboard support
• User-defined wallpaper
• Playlist creation and nested playlists.
• Social Gaming platform known as Game Centre (I love this!)
• iBooks (smaller version of the one in iPad) – Bye bye Kindle!
• Enterprise features

Of course there are many more features being introduced which we’ll get a better and closer look after the sneak peak event. iPhone OS 4.0 will be officially released within the next 2-3 months for iPhones 3GS and iPod Touch 3rd Gen and later in the year for iPad. There are also a bunch of new features for iPhone apps developer with the new iPhone OS4.0 SDK package (which includes iAds for developer – another money making opportunity!), something I am eagerly looking forward to as well.

Update: the iPhone SDK 4 BETA is now Available for Download

Check out Engadget for more details and pictures.