Hedy Lamarr was a fairly big star in the 1940s, but seems almost forgotten today, and perhaps would be, except for her striking name. (Her name was used in a joke in Blazing Saddles.) However, her personal story is much more interesting. Her first husband was a German industrialist actively working for the Nazis before World War II. During their marriage, she apparently learned a great deal about the practical aspects of designing weapons. Then, after escaping Germany and her husband, she came to Hollywood and became a star. When WW II broke out, she wanted to do something for the war effort, and teamed with a like-minded friend to design and patent an idea for radio control of a torpedo that used "frequency hopping" spread spectrum design to randomize the signals controlling the torpedo so that they could not be intercepted by the enemy. The design was never used in WWII, but, at least according to this article, it forms the theoretical underpinnings of secure wireless telecommunications today. Neat!
All that brains, and all this too: