someone suggested that the girls are taking puberty delaying drugs: http://grg51.typepad.com/steroid_nation/2008/08/are-chinese-gym.html . and those chinese girls looked way younger than 16.
LOL! The speculation is getting ridiculous. While anything is possible, the continual griping from Americans smacks of being sore losers. Phelps sets multiple WRs on the way to a record haul of medals, yet no one questions if he is on any dope. And that is the way it should be -- innocent until proven guilty. If you haven't noticed, Asians sometimes do look younger than on average. If you want a truly suspicious case that raised even my eyebrows, look at Liu Zige. She won gold for China today on a time 10 seconds (!!!!) faster than her previous fastest time -- set only this year.
Now THAT would be something to talk about.