I'm still thinking of building a bike trailer for those times when I want 1 or 2 bikes somewhere but it's raining, winter or farther than my wife will ride. I saw a picture of a really cool one on facebook that had doubled up fenders from a 30/40's car over the wheels. kinda like faired wheels on an airplane.
I built a jr dragster trailer once that used rubber torsion axles. The tongue was hinged and had a screw jack so it needed no ramps, that's the direction I'm going but want as low as possible to keep the bikes out of the wind. A set of 15x4 1/2" 10 spoke mags would look good too with some VW size tires, I'm thinking 1,000 lb axles and 39 ford teardrop or willys/indian taillights.
Maybe the axles on a subframe and airbags that let the trailer kneel? Any more crazy ideas?