Small Things Considered, Henry Petroski
The most striking thing about this book is a personal one: on the first page, he starts recounting a NPR show where the guests discussed the design of various household items, including the comments of listener phone-ins. I vividly remember listening to that show back when it originally aired, and was enrapt in the discussion. Why were things designed that way? Petroski took that theme and expanded it into a whole book, with easy-to-read commentary on doorknob positioning, phone keypads, paper bags, and office chairs. I admit, there's a few places that fell a little flat, mostly because they did not seem researched enough or he glossed over the information without explanation (something a book on explanation should avoid), but overall it's an easy and interesting read, making you think a little more about why staircases are shaped the way they are.