While many men rashly conclude that women are somehow "inscrutible" or "illogical," scientists are fortunately approaching the differences between the sexes with a more objective frame of mind, relying solely on hard data. For this reason, I was pleased to come across this research cited on Trailing Edge Blog:
A study conducted by UCLA's Department of Psychiatry has revealed that the kind of face a woman finds attractive on a man can differ depending on where she is in her menstrual cycle. For example: If she is ovulating, she is attracted to men with rugged and masculine features. However, if she is menstruating or menopausal, she tends to be more attracted to a man with scissors lodged in his temple and a bat jammed up his ass while he is on fire. Further studies are expected.