one of these?
Uni-go Trailers Texas Plus
Might be nicer than a sidecar if you make it out of an old 250cc scooter. Sidecars suck for any riding speed other than slow. The one time I rode a bike with a sidecar I hated it. A tilting trailer will solve a lot of the annoying problems and just leave the one big annoying problem of making a hitch for it.
