With the prices of the HDs going down, you could do just a regular backup of your main drive, & store it on a HD, rather than backing it up to cds or dvds. Saves time, too!
Great idea.... Do you ghost your drives or just back them up? At school, since I want all my computers identical, I set one up then "ghost" it to all the others. I can do it over the network and it's fast! I essentially copy the one to all the others at the same time.