"The biggest issue with making an image copy of your system disk
is that you must boot from another device to get a true copy.
Options include a "live" CD or bootable USB. You probably have a
copy of your favorite distribution's installation disk lying around
somewhere, so that would be an obvious choice. For our purposes
we'll use the Ubuntu 10.4 distro on a USB disk. The second option
would be to use an actual disk duplication distro like Clonezilla.
This turns out to be one of the easier ways to get the job done,
especially if you're not too comfortable with the command