Leopard firewalling
A quickie for those that want to actually get their hands dirty with OS X’s ipfw firewall: WaterRoof seems to be the tool for configuring an ipfw firewall, setting a startup script for it, etc. for Leopard. One of the nice things is that it comes with a few rules sets that make getting the basic firewall quite simple.
I’ve simply turned off the Leopard “Firewall” for now, and reverted to the tried-and-true ipfw firewall instead.