check this out...

http://www.macgurus.com/productpages/firewire/BurlyMultiDriveFWFixed.php

You could buy some car batteries and possibly take an old power backup unit and use that interface with the car batteries, then hook this bad boy up with a FW800 out to your laptop and you'd be set. Just power the thing up and down with use...

Might wanna consider some wheels for carrying it around :P
_________________________
"Fix it 'til it Breaks."

Jacob - EiC & Director of Technology
Mac Pro Quad 2.66 - 4GB RAM
160 GB SATA RAID 1 - 650 GB Storage
Quad 19" Widescreen LCDs
Accessorized to the Hilt