Need a simple way to copy your important files off to a USB drive?  This is
the sister to the xcopy script for Windows.  Use this for Mac or Linux, as
long as you have the simple and powerful rsync installed.  Substitute your
username and your volume destination name.  Written syntax for the Mac
viewers.

#!/bin/bash

echo "Executing rsync";
rsync -avz /Users/username/Documents/ /Volumes/bk/Documents/
rsync -avz /Users/username/Library/Caches/ /Volumes/bk/Caches/
rsync -avz /Users/username/Library/Thunderbird/ /Volumes/bk/Thunderbird/

Need to backup over ssh?  Easy!

rsync -avz -e ssh remoteuser@remotehost:/remote/dir /this/dir/ 

The beauty of rsync is how ridiculously fast it works.  It moves the
changes in files only.  If I change a few files, the backup takes a
minute or so.  If I change nothing, it takes a couple of seconds to sort
through and see that nothing changed.  Great for time and bandwidth!