How Americans came to have cup holders in their cars.
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Henry Petroski is the Aleksandar S. Vesic professor of civil engineering and a professor of history at Duke University. He is the author of a dozen books on engineering and design, the latest of which is The Toothpick: Technology and Culture.
Photographs of: drive-in fromCorbis; 4Runner cup holders and Audi cup holders by Lori Johnson.