I just came across this cart and thought I would revive this old thread incase there is anyone interested in it. It reminds me of the Sherpa Cart that CityBoyGoneCountry posted. It is expensive though. I don't remember seeing it posted before. Ravenlunatic just posted this website on the Kelly Kettle thread and I was browsing and came across this Water Strider Truck-n-Trailer (you might have to scroll down to just below the half way point to see it):
http://www.waterstrider.com/rafting-gear.htm#trailer The Sherpa Cart looks like it would hold more stuff and it was made for backpacking.
Some interesting stuff on that site.
Joy