I recently came across this article where a person basically had external male and internal female organs, he didn't know he was 'intersex' until he happened to be getting an ultrasound for a completely different issue.
Intersex is a broad term:
Intersex, in humans and other animals, is the presence of intermediate or atypical combinations of physical features that usually distinguish female from male. This is usually understood to be congenital, involving chromosomal, morphologic, genital and/or gonadal anomalies, such as diversion from typical XX-female or XY-male presentations, e.g., sex reversal (XY-female, XX-male), genital ambiguity, or sex developmental differences. An intersex individual may have biological characteristics of both the male and the female sexes. (wikipedia)
Food for thought: is this a stage in human evolution? If humans were to survive 5 million years from now, would they have evolved into a sexless species?