Alice Dreger, “Sex Beyond the Karyotype,” in Controversies in Science and Technology, volume 2: From Chromosomes to the Cosmos, edited by Daniel Lee Kleinman and Jo Handelsman (Mary Ann Liebert, Inc, 2007).
Designed as a handy introduction to the nature of sex and gender, this is meant to be (and I think succeeds in being) a highly accessible explanation of why it is silly to think of your sex as being what you think your chromosomes are. Perfect for people who need to be less naive about sex and gender (undergraduate students, doctors, judges, the occasional feminist academic…).