The free iOS4 update for iPhone 3GS, iPhone 3G and iPod Touch is out, you can upgrade to the latest version by using the iTunes upgrade option. If you do not know how to upgrade to iOS4, read our earlier article on How To Upgrade to iOS4 on iPhone 3GS, iPhone 3G and iPod Touch.
One of the new features in iOS4 includes multi-tasking, this feature is available only for iPhone 3GS and certain iPod Touch devices.
To multitask with iOS4 on an iPhone or iPod Touch, just double-tap on the home button when an app is open, this will bring up new apps for you to choose from at the bottom of the screen.
You can scroll through all the open apps by shifting it to the right or left of the screen. Once you click on the app it will seamlessly switch between the current one and the one you chose to multitask with.
To close an open app, just press and hold the icon and click on the "-" symbol at the left corner, this will close the app altogether. Have fun multi-tasking on your new iOS4 on an iPhone or iPod Touch.