Norton Ghost allows you to make a duplicate copy of the drive.
I use it at work to upgrade my users hard drives. Let's say that have a 6.4 GB hard drive that is almost full. Instead of taking that new 10 GB hard drive and reinstalling the operating system, software, and data files, I use Norton Ghost to copy the data from the 6.4 GB hard drive to the 10 GB one. So instead of taking a day to reload everything, it only takes me about an hour to upgrade that individuals hard drive.
It can also be used if you are going to be rolling out several identical systems at once. You install everything on one system, the use Norton Ghost to duplicate or clone the drive over to the other systems.