Those with no monetary need to reign in their flights of fancy do all kinds of entertaining things. Round-the-world ballooning has practically been done to death by moguls. 19th century rifle heiress Sarah Winchester built her house into a 160-room maze, the better to protect her from ghosts. The Cone Sisters collected art in the Teens and Twenties, just like British adman and Thatcher confidante Charles Saatchi does today. (Determining the relative merits of their collections is left as an exercise for the reader.) Museum-building has long been popular, and philanthropy is a perennial winner, from the Ford and Carnegie Foundations to today’s Bill and Melinda Gates Foundation or Soros Foundations. But more Quixotic efforts are ever so much more interesting! Martin Gardner’s Fads & Fallacies in the Name of Science cites the case of financier Roger Babson, who devoted some of his fortune to the Gravity Research Foundation, dedicated to inventing an anti-gravity device. On a more earthbound note, the Clay Mathematics Institute was founded by money manager Landon Clay; "dedicated to increasing and disseminating mathematic knowledge," it offers million-dollar prizes for solutions to some of mathematics’ most important unsolved problems, including a final answer to the question of whether P = NP and a proof or disproof of the Riemann Hypothesis. And then there is the strange case of Marc Sanders, an amateur philosopher who has spent thousands of dollars to have experts on metaphysics review his manuscript. Godspeed, Mr. Sanders — debating the necessity of the divine is a hell of a lot more interesting than taking a balloon ride.