Protect your privates!
In view of all the brute force attacks still being attempted against Secure Shell (SSH), we have long since been extolling the virtues of forgoing passwords and moving to RSA/DSA keys instead.
While key based login indeed nicely addresses the problem of password guessing attacks, it looks like many a Unix admin has been less than diligent in the implementation. In pretty much every Unix security audit recently, we've come across unprotected or badly protected SSH private keys (id_dsa, id_rsa). Some reside plain flat out in the open, in /tmp and such. Others are found in world-readable tar "backup" archives of user and administrator home directories. Some are even built into home-grown Linux RPM and Solaris PKG packages, ready to be plucked off an install server.