A few years ago I noticed that OS X started offering “FireWire” as one of the tcp/ip connection types, alongside ethernet and modem. Sounded intriguing, but couldn’t imagine a situation where it would be useful.
The brilliance of this arrangement dawned on me over the past couple of weeks, as I found myself in a house with a DSL connection but no router — DSL modem feeding their eMac directly. To get my laptop online without taking their machine off the network, just enabled connection sharing on their Mac, connected a FireWire cable from it to me, and I was online, slickr-n-snot. All of my posts here over the past two weeks were made over FireWire.
Heck, you could even plug a laptop into the back of an external FireWire drive. Effortless.