No doubt you know that sharing your internet connection on your Mac is easy. For instance, if want to turn any Mac with a built-in Airport card into a wireless router (e.g. with a cable or DSL modem plugged into the built-in ethernet port), all you have to do is go to the Sharing pane of your System Preferences select it and hit start. However, what if you want to do something a little bit more complicated? This tutorial covers some other ways for turning your Mac into a router, including over FireWire and adding a second ethernet port via USB (which can be really tricky).