The Advance Utility: dd
This is where things get more interesting. dd is a command line utility and is far more flexible than the Ubuntu simple backup suite. It also does many things that the Ubuntu Simple Backup Suite can't, such as an exact hard drive clone and the ability to restore even if you cannot boot into Ubuntu desktop.
There are three main commands which you will need to remember to do a full backup and a full restore. The first one is:
sudo fdisk -l
which will list all of your drives and their respective Linux names. The Linux names (/dev/sdx for example) are important for dd so it knows where its backing up from and restoring too. The second command which you will need is:
sudo dd if=/dev/sdx of=~/backup.img
This will backup /dev/sdx (you will need to put your own Linux name in from the first command) to the image file backup.img and store it in your home directory. You are then free to gzip it or put it in a safe place on another computer. Another note about this command, you can use /dev/sdx1 as the input file (if) to just backup the first partition on /dev/sdx.
The final command you will need is just switching the input and output files to restore the backup:
sudo dd if=backup.img of=/dev/sdx
You may have to use this command from a LiveCD or another environment as you can't be booted into the system when restoring to it, but that should restore the backup and make your Linux system exactly the way it was when you performed the backup. It may complain about time jumping etc, do not worry too much about these warnings as they will fix themselves.