(written from a Production point of view)
Joshua Greene is a child actor who appeared in 2009's Star Trek as a body double for James T. Kirk. He was used in place of actor Chris Pine for a sequence in which Kirk runs into a cave. This was done to give the illusion that the entrance to the cave was bigger than it actually was. (IMDb resume, Star Trek DVD featurette A New Vision)
Greene will also be seen in the upcoming independent comedy film The No Sit List. In addition, he has appeared on the internet shows Comedy Gumbo and The Drumbone Story, as well as a commercial for the Family Violence Prevention Fund.