Answers to Puzzle Contest (from the winner):

"eightpenny. An eightpenny nail (8d) is 2.5 inches long."

Winner: Graeme Black, Vacaville, CA. Only Graeme, Shirley Wolf, and Nathan Glasser got this one. Almost everyone else answered centimeter or centimetre, and a few people noted that "an inch is 2.5 centimeters" and not the other way around, assuming I made an error in the puzzle. For once I did not make any errors (a New Year's treat for everyone, especially myself), and centimeter/centimetre was simply an unintended red herring that is not correct.

Contest Statistics: Newsletter sent to 279939 subscribers, 19 answers submitted, 3 answers correct, 15.79% accuracy. Chance of a correct answer winning: 33.33%. This was a pretty tough one!