Goggles...you act like this would work in any other industry. If the boss wants to come into your workstation, unannounced even, it's a non-starter, he or she's going to do it. He's not doing it in-flight, and if it's interrupting your "PIC" duties then as said earlier politely tell him so. Any other worker in any other industry has just as much "invested...in real terms" as we do in our airline, whether that's Continental, Delta, Ford, or IBM, it doesn't give us the right to keep him out of our workstation, in this case the cockpit, especially if he's doing it at an appropriate time. Would you rather he be on your flight and not ask your opinion about how to make the company better, regardless of whether or not you think he'll actually listen to you? What would you do if you were in charge?