>A slightly different spin on tedd's approach of using a second hard 
>drive is to use Speed Doubler 8's copy. It automatically intercepts 
>the drag and drop Finder copy (OS 8/9) and provides a "Smart 
>Replace" option. "Smart Replace" only replaces the files on the 
>target HD that haven't changed. This way my backups (even though I 
>drag and drop all folders) take only a few minutes after the initial 
>backup. Maybe someone can write a smart replace copy utility. Just a 
>thought.
>
>Brian

FolderSynchronizer is a shareware utility that does just that (and 
more) (also in X) http://www.softobe.com

Martin