Use ssh as a VPN

http://fosswire.com/2008/06/30/using-ssh-as-an-ad-hoc-vpn/

Configure iptables

http://www.howtoforge.com/bash-script-for-configuring-iptables-firewall

Update your kernel

http://www.cyberciti.biz/tips/linux-kernel-vulnerabilities.html

Intrusion detection for PHP

http://www.howtoforge.com/intrusion-detection-for-php-applications-with-phpids

Find and replace weak RSA keys

http://www.cyberciti.biz/tips/ubuntu-debian-linux-openssl-dsa-1571.html
http://www.cyberciti.biz/faq/howto-regenerate-openssh-host-keys/

Anonymous IM

http://code.google.com/p/torchat/

Quickies: wipe your hard drive

http://www.linux.com/feature/135944

An easy ARDagent fix

http://www.tuaw.com/ardfix/

Remote-unlock an encrypted root partition

http://www.howtoforge.com/unlock-a-luks-encrypted-root-partition-via-ssh-on-ubuntu

Chroot sftp with JailKit

http://www.linuxjournal.com/content/creating-chroot-sftp-jails-jailkit

Wipe your iPhone

http://www.hackaday.com/2008/06/10/wiping-an-iphone-more-thoroughly/

Tunnel torrents

http://whalesalad.com/2006/08/27/tunneling-BitTorrent-over-ssh/

RAID primer

http://www.howtoforge.com/redundant-array-of-inexpensive-disks-raid-technical-paper

Pen-test your systems

http://www.linux.com/feature/138325

Protect your email address

http://hivelogic.com/articles/2008/06/enkoder-mac-osx-is-back

Quickies: backup over ssh

http://www.arsgeek.com/?p=650