The iPhone iOS4 update brings with it a whole load of new features including multitasking for the iPhone 3GS, iBooks, Homescreen wallpapers and Folders that allows you to organise your homescreen.

Here's how to update your iPhone 3G and 3GS to iOS4.

Note: You will need either a PC or Mac with iTunes installed to install iPhone iOS4.

1. Plug your iPhone into your computer using the USB provided
2. iTunes should pen and detect your iPhone automatically
3. Ensure your phone is fully synched and backed up on your computer
4. If you don't get an alert telling you the software is available, click on the Check for Update
5. Allow the computer to download the firmware update
6. When the update has downloaded, it should start to automatically update your iPhone
7. Do not remove the USB connection when the iPhone is upgrading the firmware as this will corrupt your iPhone
8. When the update ios complete, your iPhone will restart itself This may take a fair while, but be patient!
9. When your iPhone turns back on, it should be updated to iPhone iOS4

Take a look at our iPhone 4 user guides to find out how to change the wallpapers, use multitasking, organise your homescreen into folders and add extra Exchange accounts to your updated iPhone 3G or 3GS.