> Has anybody ever seen a rack for hauling a kayak that would slide into a
> receiver hitch on a pickup truck, something along the line of the ones
> made to haul bicycles.

I've seen all sorts of kayak roof mount systems, but nothing to mount in the receiver hitch. How would this work? On a bike rack, they are mounted "sideways". It seems to me that you would have to have a very short yak, or a very w-i-d-e vehicle. ;-)