"A lot of [James Bond creator] Ian Fleming's ideas, when he was personal assistant to the Director of Naval Intelligence [during World War II], were just plain crazy," Admiral Denning recalled. "One had to accept this element of wildness in all his thinking. But a lot of his far-fetched ideas had just that glimmer of possibility in them that made you think twice before throwing them into the wastepaper basket. Just before the Dieppe raid, for instance, he had the idea of sinking a great block of concrete with men inside it in the English Channel to keep watch on the harbour through periscopes. We never did it, of course, but it might have worked."
[007 started out carrying a Beretta pistol. From Dr. No forward, however, he sported a Walter PPK. Why the change? Fleming was informed by friends one day that the Beretta was a gun for ladies!]
Sources
John Pearson, Life of Ian Fleming; GQ, Apr 2003, p. 104