Apple has recently released iOS 4 firmware for iPhone 3G, iPhone 3G S, iPod Touch 2G and 3G ( 3rd generation) devices but not all the features of apple OS firmware 4.0 work on all iPhone models.
iPhone 3GS support all the features of iOS 4 but iPhone 3G does not, read here about those features which are not supported in iPhone 3G. Today we are telling you about a cool much awaited feature introduced with firmware 4.0 which is changing the home screen wallpaper which still does not work with iPhone 3G, however you can easily change the home screen wallpaper in iPhone 3G if you jailbreak it.
Follow the procedure below to change the home screen wallpaper
1. Go to Settings >> Wallpaper
2. Tap the wallpaper sample image and then select an image from camera roll or from photo library
3. Tap Set to set the image as wallpaper
4. Now it will ask whether you want to set the image to lock screen, home screen or both
5. Press the home button now to see the new set home screen wallpaper.