Here is a quick and easy way to save and restore hard disk images using dd, netcat and gzip.

To Save An Image:

On the server: nc -l 7000 dd of=Output.img.gz
On the client: dd if=/dev/sdb gzip -9 nc 7000

To Restore:

On the client: nc -l -p 7000 gzip -dc dd of=/dev/sda
On the server: dd if=Output.img.gz nc 7000

I just boot the client using an Ubuntu live-cd, all the neccessary tools are already installed. I store my images gzipped to save space, I just copied a 40 GB disk and the image file compressed down to 4.4 GB!