Years ago there was a product called TrailorOn that I'm certain Burly most have copied the idea. Unfortunately, the company went bankrupt by I have one that was made for my Dahon. It works very well but I never really used it. The good thing about the device was that it could use any push cart or even a shopping carriage.
All you need is a farily long PVC pipe and two thick rubber bands.
http://www.rovingfestival.com/equipm...andtruck.shtml