With a FW port at my Mac and my x86 Audigy soundcard I could try this, yet FW cables quite expensive.I don't know about your whereabouts, but in the Netherlands FireWire cables are expensive too.
A local shop here in germany wanted 15€ for a 3m calbe. I think i could by 30m of Ethernet cable for that :/
The silly thing is, it's just a couple of wires going through that cable, and fitting the cheap connectors isn't complicated either. I've seen local pricing range from 6 euros to a stunning 35 euros, for the same 6 ft by 6 pin cable. I guess it's the unwitting dv-editing general public that happily overpays for simple accessories, as they are used to in the photography and video market.
They are probably not mass produced and I guess will never. A 6/4 cable for the camera will mosty be included and think no admin will buy several meters of FW cable to set up iee1394 network :)
But..., damn, isn't using the Cube as a router kindof blasphemy? ;-)Well, it leaves a lot of resources for a webserver, a mail server, and let's not forget Bayesian spam filtering, and you could of course add some media server, phone answering service and much more. You could still even play Shishen-Sho under KDE! *And* your Cube will fit into just about any niche or corner, and stops books from falling over on any everage shelf. :-)
Yes, all this might work, but it's still abuse. Let the cube spend the time until entropy finally breakes it more gracefully and sell it at ebay hoping the next owner shows more appreciation for it :)
-Thomas