You're a smart guy, but thanks to your good looks, people easily forget your above average intelligence. The best way to keep your office mates knowing that you're mind is as sharp as a tack? Keep a good book on your desk. And not just any book. How about The Catcher in the Rye by J.D. Salinger?
The protagonist, Holden Caulfield, has cemented himself in American history as a painfully angst-driven sixteen year old who won't go down without a fight. The book is an absolute classic that easily deserves a spot in your home library or office bookshelf. You'll find new insight each time you crack it open.