I just came across this chart that claims to predict what
sex a child will be at birth. The website states it's 99% accurate.
Its easy to test as long as you know both of the following.
A) the month the child was born and
B) the age of the mother at conception.
http://mypage.direct.ca/j/jfeng/gender.htm
Lets test the accuracy of this, I'd be surprised if it works.

I post results as soon as I get some ages.