Apple's Mac OS X hardening guide

Apple recently posted a 240-page guide on hardening Mac OS X 10.5 (Leopard). It's pretty comprehensive, where its 13 chapters cover everything from an overview of Mac OS X's security architecture and its UNIX underpinnings to securing accounts to permanently deleting stuff from Time Machine backups to encrypting your virtual memory and much more.

If you manage Macs in your network, or are a Mac user yourself, this is a must-read.

UPDATE: Apple's security configuration guides for earlier Mac OS X versions, as well as the server version, are available here.