A while back Apple did a preview release of IP over Firewire. I didn't really pay much attention to it since it isn't often that I'm doing stuff with two macs. The other day I was grabbing the latest dev tools and decided to download it just so that I would have it handy.
Today I zipped down to my parents place and decided to give it a try, since there was some software I'd downloaded that I wanted to make available to them. Once installed it, I plugged the firewire cable into each computer and was able to see the other under file sharing. This will make it much easier to send files back and forth to them when I'm down visiting. And it means one less cable to carry around with me. I have heard reports of at least one person having a kernal panic when they tried this, but I haven't seen any sign of anything like that yet (*knock on wood*). Hopefully Apple will roll this into a real release sometime soon.