Believe it or not, we've seen something like this before
-- out of Japan, naturally -- so we're a bit surprised to see a patent app roll in from Samsung for a phone capable of tracking a woman's fertile periods. The idea is to keep the user updated on her "baby" and "no baby" times of the month when she places a call by measuring distance to the eardrum (using either ultrasonic or laser sensors) combined with infrared to get a temperature reading. This corresponds to a woman's basal body temperature cycle, which in turn maps to her menstrual cycle. In Japan, the concept was intended to boost birth rates by keeping couples in the know on exactly when they might have success -- but elsewhere we imagine the intent might be just the opposite. We'll leave it to our readers' active imaginations to decide just when and how the user should be kept abreast of said information.
[Via Unwired View