Apple released its Security Configuration Guide for Mac OS X 10.5
"Leopard" on Monday, a 240-page document that describes ways for
sophisticated Mac users to further secure their systems.
The manual
includes an overview of the Mac OS X's security architecture and advice
on hardening the operating system against external attackers as well as
locking down the system to protect against unauthorized access by
people with physical access to the system. The instructions make
extensive use of the command line, and Apple warns readers that only
technically-adept users should use the guide.
http://www.securityfocus.com/brief/747