No, not us. :-) My sister Rachel found out the sex of their third little baby on her birthday, and kept it a surprise until her party the following night. We decided to guess whether they were having a boy or a girl by wearing either blue or pink. I couldn't decide, so I wore both colors.
After Rachel opened her presents, she gave us the best gift of the night. On Rachel's cue, Miles opened his button-up shirt to reveal a painted t-shirt that said, "It's a Boy!"