Hidden doors -- This company makes cabinets, bookshelves and anything you can think of that fits your existing doorjambs thus hiding the door (and also making use of the space) Not sure I like the idea of a 'gun cabinet' door.
Me and Neil were chatting about paint colours for No. 42 the other day. I asked him which wall sample he preferred in each of the rooms and he replied: "I don't mind, as long as the whole house isn't grey. These samples all look grey" Oopsy!