Someone check the math- How old was Obama's Mom when he was conceived?

Okay, there is no way this is true, and I'm unable to piece the secrecy surrounding our good President's birth (I heard from some liberals that he was born of a virgin mother), but I did pick up this fun fact on Jim Treacher's blog- Barack Obama was conceived out of wedlock when his mom was barely legal!

Ann Dunham Soetoro was born on 11/29/42, she married Barack Obama, Sr. on 2/2/61, and their son was born on 8/4/61. So lil' Barry would've been conceived somewhere around his mom's 18th birthday, most likely before, with a man who was not her husband. And his parents' subsequent marriage wasn't even legal, because Barack Sr. was still married to a woman in Kenya.

Huh. It really is an interesting story that you probably didn't know. You probably heard that he was black though, right?