One of the local stations randomly runs an Australian children's show called "The Saddle Club". I was channel surfing one day a few months back and stopped on it as this young guy guest-starring on it looked incredibly familiar. Could it be? I imdb'd it and yes, that was a very young Chris Hemsworth. Recognizable even from ten years ago!
But just from his brief scene in Trek, I knew that guy was gonna be a superstar - you couldn't take your eyes off him when he was onscreen. And he was emotionally compelling in such a small role.