My current rsync script for cloning my HD ( OS X 10.8 ). The rsync flags are what Carbon Copy Cloner uses.

ccc.sh

#!/bin/bash
target_drive=/Volumes/Clone
if [ -d $target_drive ]; then
  echo "Last backup: " `cat ~/.last_backup`
  sudo echo "And we're off!"
  echo "Started: " `date`
  echo `date` > ~/.last_backup
  sudo time nice -n19 rsync -A -X -H -go --numeric-ids -D --protect-decmpfs -l -rtpx -N --fileflags --force-change --protect-args --delete-before --ignore-errors --filter='._/Users/i/.rsync-filter' // ${target_drive}; bless -folder ${target_drive}/System/Library/CoreServices
else
  echo "${target_drive} is not mounted"
fi

Why "sudo" the echo on line 5? This just helps me remember to type in my password by making me do that first thing. I would sometimes see the words "Started: " from line 6 and think it had started, then come back to it later to find out it's been waiting for me to type my password -_-