One thing has nothing to do with the other. Carbonite is an online backup service. I always recommend a layered backup approach - a local backup to an external hard drive and a remote backup. The remote backup could be done by burning CD/DVD-Rs and then
putting the discs in a safe place but many people won't do this regularly. For them, an online backup service like Carbonite or Mozy (my preference) is ideal. More info:
http://www.elephantboycomputers.com/page2.html#Backing_Up
MS-MVP - Elephant Boy Computers - Don't Panic!