Bikes At Work is a maker of modular bicycle trailers for hauling cargo. What makes these trailers unique is their modular design, which allows the user to extend the length of the trailer to accommodate longer loads.
Built from extruded aluminum, they look like a ladder with wheels. The simple robust design should be strong enough to carry anything you have the strength to tow. Prices range from $450 to $570, which means they should pay for themselves in a few months with regular use.