Check out *www.thefreecountry.com/utilities/backupandimage.shtml for some free hard disk imaging utilities... Also, some backup utilities are also included....
Do note, imaging and backing up are not the same... Norton Ghost does HD Imaging (take a full snapshot of the hard disk), whereas backing up is a more generic term that is used for creating backup copies of one or more files... If your hard disk crashes, you will need an image of it to restore it quickly, otherwise, you have to restore files from backup and reinstall programs...
Arun