Back in time is a framework for rsync, diff and cron for the purpose of taking snapshots and backups of specified folders. it minimizes disk space use by taking a snapshot only if the directory has been changed, and hard links for unmodified files if it has. the user can schedule regular backups using cron.
this is the gnome front-end for the backintime-common package. if you also install the package nautilus-actions, it can be integrated with the nautilus file manager to provide context-menu options.