Rdiff-backup

http://www.linuxjournal.com/article/10701?page=0,0 [ rdiff incremental]
http://arun121.blogspot.com/2009/10/remote-incremental-backup-with-rdiff.html [ incr backup]
http://www.susethailand.com/suseforum/index.php?topic=1403.0[suse+rdiff-backup]
http://blog.beyond-syntax.com/2007/10/automatic-backups-using-cron-and-tar/
http://www.linode.com/wiki/index.php/AutomatedRdiffBackup
http://defindit.com/readme_files/ssh.html
http://en.kioskea.net/faq/746-rdiff-backup-making-effective-and-incremental-backups
http://lpi.universe-network.net/doku.php?id=wiki:certification:lpic301

http://dave.thehorners.com/tech-talk/unix-linux-bsd-osx-etc/87-rdiff-backup-remote-incremental-backup
http://library.linode.com/linux-tools/rdiff-backup/
http://drup.org/unattended-rdiff-backup-howto [****]
http://administratosphere.wordpress.com/2007/12/13/using-opie-on-fedora-7/ [opie]
http://www.delta-xi.net/index.php?/archives/16-OTPs-Using-sKey-with-SSH-via-OPIE.html
http://www.spencerstirling.com/computergeek/rsync.html
http://www.rho.cc/index.php/linux2/46-1key/66-how-to-setup-opie-with-pam-on-linux
http://www.antionline.com/showthread.php?t=238351
https://help.ubuntu.com/community/SingleSignOn