I love the single wheel motorcycle trailers and other extra lightweight alternatives however those are way too much money for my expected trailer use. My plan is to instead buy or build something similar to this for the extra cargo capacity I need for weekend camping expeditions and extended trips when traveling with two people on board.
View attachment 2452
This one is available from harbor freight for about $370 and weighs about 145 lbs empty.
http://www.harborfreight.com/600-lb-capacity-78-inch-tag-along-trailer-66771.html
I know that between the extra weight and added aerodynamic drag pulling this type of trailer would hurt my fuel efficiency however I seriously doubt I would lose more than 25%. Even if my highway number was lowered to 'only' 60 MPG it would still be worth it as that is much better than anything else available while carrying the same load.