Another way to do this would be to build a router from an old 386 machine or something to that nature. Use a program that runs from a floppy called freesco, or my personal favorite Smoothwall. This is basically a 30 meg program you can load to a small hard disk and it turns the old clunker into a linux firewall router. Fully customizable and really easy to set up. Has an interface much like a regular router. Uses 192.168.1.1 to configure the router settings in a browser, or if you feel geeky that day, you can access it in the terminal.