Hi Tony,
You're right, there's any number of gadgets that one could buy ... including two things strangely omitted from your list,
viz. an expensive chronograph wristwatch (okay, I own one ... but it was a gift!
), and a large set of embroidered wings (sewn on the left breast of one's jacket ... in a pinch, a hat with the word "PILOT" in large letters will do!).
Notwithstanding the above, just go to any golf supply store if you want to see a
really impressive collection of useless accessories for sale. With apologies to any golfers who may read this, I never could understand the market for the many tacky desk items out there: okay, you play golf, good for you, but why are you so proud of that fact? The really good golfers have no need for
this sort of stuff.