Just found the web page from a guy who built one heck of a monster adventure rig (actually, he built 2):
http://www.robgray.com/graynomad/wothahellizat/index.php
Here is a pic of the first rig he built:
http://www.robgray.com/graynomad/wothahellizat/index.php
Here is a pic of the first rig he built: