Boy or girl??

OK, so about 90% of people think it's going to be a boy. How do people know these things? Is there postgraduate work you can do in gender pre-identification? Oh, well she's carrying low. She's carrying straight out. You can't tell from behind. Depends on whether mom's beauty has been "stolen", or something. When she walks up stairs, the first foot she steps with is opposite her dominant hand. OK, I made that last one up, but there seems to be a lot of theories out there about how to tell. I thought the whole idea of "not knowing" the gender was to actually not know the gender. I don't really care what gender the baby is, but I'd be a little bummed if all these ways to determine the gender end up being more reliable than reading tea leaves...kind of like finding out that everyone subscribed to a biological Ain't it Cool News and then spilled the spoiler:). However, the statistician in me understands that with boy/girl, it is the flip of a coin so you're going to be right half of the time no matter what. But it will still be super funny if everybody's wrong and it's a girl...