A hermaphrodite is an organism that has both male and female sex organs. A good example would be a snail. When snails mate each one's male part fertilizes the other's female part.
As far as I know there is no such thing as a human hermaphrodite. However there is a rare case of genetic males (with X and Y chromosomes) who, due to a mutation, do not express the gene for testosterone and therefore have the external characteristics of females (If you're interested, there is a very interesting book called "Middlesex" which describes such a case). Women who are genetically males cannot become pregnant because they do not have ovaries and a womb. There is a myth that these women are usually very tall and very beautiful.
Nicole Kidman is relatively tall (about 1.78 meters I believe) and is considered beautiful. She has 2 adopted children, so there have been rumours that she is a genetic male. I have also heard rumours that she is a lesbian (supposedly her marriage to Tom Cruise was a cover for both of them, it is rumoured that he is gay). However very shortly before she divorced Tom Cruise there was some story that she had a miscarriage. So, believe what you will...