Tom--
you may have to start talking to the lawyers! if you thought golf course design was difficult before, try adding in a layer of intellectual property laws (e.g. copyright and patent laws)
Paul:
I've had a clause in my contracts for many years that while the client owns the golf course, I retain the copyright to the design as a work of art, so that if someone does a knock-off, I'm the one who can sue.
Nevertheless, I know the reality is that I would spend a fortune on legal fees and be lucky to get a dime in return. I had an arbitration hearing once years ago about whether a client owed me for the routing I'd done, and the arbitrator ruled that them having changed two holes made it a different plan, so I wasn't entitled to anything!
Of course if I sold my rights to Disney I am sure they would manage to collect on them.