Neil's Open Source & Linux Blog

Using Rsync and SSH : "covers using cron, ssh, and rsync to backup files over a local network or the Internet"

rsync is an open source utility that provides fast incremental file transfer, available under the GNU General Public License version 2. rsync is hosted at http://samba.org/ .

View the current rsync man page in HTML.

Easy Automated Snapshot-Style Backups with Rsync explains how to create rotating backup using rsync -- includes bash scripts!

HOWTO Backup Your Mac With rsync includes instructions on how to use the GUI front end to RsyncX, plus command line and script options.