Here's all the gory details on the central backup server I've mentioned in various posts on here. Combines the storage goodness of ZFS, with the network transfer goodness of rsync and openssh, with the all-around beauty of FreeBSD. Enjoy!
Rather than copy/paste or re-type it all, here's the link to the thread on the FreeBSD Forums:
Remote backups server using FreeBSD, ZFS, and Rsync