In a previous post we told you that multitasking will be possible on older iDevices when you jailbreak your device and edit the plist-file called N82AP.plist (3G). But that’s not the only feature that will be disabled on older iDevices in OS 4.0. When you got a iDevice older than the iPhone 3GS or the 3th generation iPod Touch, a costum backround will also be disabled in OS 4.0. But guess what, there is always a solution. (wallpaper and multitasking solution after the break).
First you need to jailbreak your device, after it is jailbroken install OpenSSH.
Than browse to /System/Library/CoreServices/SpringBoard.app/N82AP.plist via SSH and copy the file to your Mac or PC. Open it on your Mac or PC with an app of your choice “for example TextWrangler” so we can edit the file.
Add the following string to enable wallpaper:
Or the following string to enable multitasking:
Now copy the edited file back to you iPhone and replace it with the older one. Now reboot your iPhone and you got multitasking and wallpaper on your iPhone 3G.