I recently purchased a Nova Craft Prospector 17. I haul it primarily with a full sized long bed pickup with a Hi-Rise fiberglass cap. While searching for a decent used trailer that I can convert to a canoe hauler, I decided I needed something in the interim. I purchased a Haul-Master bed extender at Harbor Freight for $49.00 and it might be the best $49.00 I ever spent.
It makes loading and securing the canoe in a truck equipped with a cap a breeze. The extender comes complete with all the hitch pins and cotter pins needed to assemble it. It is sturdy and secure and it can also be mounted vertically so that the canoe can be carried over an open pickup bed using foam blocks on the cab of the truck.
It's obviously not for everyone, but for people with pickup trucks it's well worth a look.