rsyncbackup is a perlscript that reads configuration files for sources and destinations, and feeds the rsync tool with the appropriate parameters. rsyncbackup is written on Mac OS X, but will probably work on every system that have both perl and rsync installed. rsyncbackup is GPL licenced.
I wrote this script for personal use, but since backuping is such a good idea, maybe you want to use my script as well. Feel free to do so.