Multitasking and Background Wallpapers are two prominent features of iOS 4.0 – However If you upgraded your iPhone 3G to iOS 4.0, you would notice that it remarkably makes your Phone sluggish, therefore Apple by default disables the Multitasking on iPhone 3G.
There is a very handy little App ‘zToggle’ in Cydia App Store that would Enable or Disable both Multitasking and Background Wallpaper on your iPhone 3G. However in order to use Cydia App store you would have to Jailbreak your iPhone 3G (Complete Step by Step Guide can be found here) Simply search for ‘zToggle’ in Cydia App store and Install this app and from there you can disable or enable Multitasking on your iPhone 3G. Simple isn’t ?!!!
Well, waiting for iPhone 4G to arrive here in Saudi Arabia. What I feel about iPhone is, iPhone every release come with great disadvantages and stupidities inside, after release when people complaint about that issues Apple guyz fix that.