I have a Kendon dual trailer, and I recommend it highly. It "stands up" in my garage, so it doesn't use up all the floor space. I added a Condor chock, which also works great. Mine's an older model, I think the Condor is standard on the new ones.
I've taken this from St. Louis to Tornto Canada, Asheville North Carolina, Washington DC, and Colorado, as well as all sorts of local hauls. Many local hauls when my Royal Enfield stopped running in interesting places. It was a Royal PIA!
However, if storage space for a trailer is especially tight, these things have gotten pretty good buzz:
http://trailerinabag.com/index.htmlAnd the dual trailer hauls fine with one bike, and you can share driving and truck gas with a buddy: