(written from a Production point of view)
Gregory Phillip Grunberg (born 11 July 1966; age 49), known simply as Greg Grunberg, is an actor from Los Angeles, California, who voices James T. Kirk's stepdad in Star Trek. This character was originally meant to be Kirk's uncle and was played by Brad William Henke in the film, but Henke's scenes were deleted and the character's voice-over dialogue was re-dubbed by Grunberg.
Grunberg was offered the role of Chief Engineer Olson in Star Trek, but he could not accept the role as he was shooting a film he co-wrote and co-produced called Group Sex. The role of Olson was ultimately given to Greg Ellis.  Although Grunberg was not able to work on the film during principal photography, he found a way into the movie before it completed post-production.  He has been friends with Star Trek producer and director J.J. Abrams since childhood and has participated in many of his projects.
Grunberg is currently best known for his role as telepathic police officer Matt Parkman on the hit NBC series Heroes. Zachary Quinto, who plays Spock in Abrams' Star Trek, is also a regular on Heroes, as is Cristine Rose. Many other Star Trek alumni have appeared on this series, including Michael Dorn, Dominic Keating, Malcolm McDowell, Nichelle Nichols and George Takei.
Before Heroes, Grunberg starred in two series from J.J. Abrams. The first was Felicity, in which he played Sean Blumberg. The next was Alias, in which Grunberg portrayed CIA field agent Eric Weiss. Grunberg also made an uncredited appearances in the Abrams-directed pilot episode of Lost (co-created by Abrams and Damon Lindelof and co-starring Terry O'Quinn and Daniel Dae Kim) and the pilot for Abrams' series What About Brian. Grunberg even had a brief role in Abrams' motion picture directorial debut, Paramount Pictures' Mission: Impossible III (2006) along with Simon Pegg, who played Montgomery Scott in Abrams' Star Trek, and Tracy Middendorf.
Grunberg made his television debut with a small role in the 1990 CBS movie Stolen: One Husband, starring Bruce Davison and Julie Warner. He later made guest appearances on such shows as Melrose Place (with Rosana DeSoto), Diagnosis Murder (with Susan Gibney), Profiler (with Cyia Batten), The Dead Zone (starring Nicole de Boer), House (starring Jennifer Morrison), and Monk (with Stanley Kamel and Peter Weller). In 2001, he made three appearances on NYPD Blue, algon with Gordon Clapp Juliana Donald.
In 2002, Grunberg starred in the NBC series The Jake Effect with one-time Star Trek: The Next Generation guest performer Nikki Cox. The series was canceled before it even aired, but six of the seven episodes produced were shown on the Bravo channel during its "Brilliant But Canceled" block.
Grunberg's early feature film credits include small roles in The Pallbearer (with Mark Margolis), Senseless (with Cyia Batten, Ivar Brogger, Brad Dourif, Jenette Goldstein, and Richard McGonagle), BASEketball (with Raphael Sbarge), and The Muse (with Dakin Matthews and Concetta Tomei). He also had a major supporting role in the 2000 science fiction thriller Hollow Man (with Jimmie F. Skaggs and J. Patrick McCormack). More recent films, in addition to Mission: Impossible III, include Austin Powers in Goldmember (with Tommy "Tiny" Lister, Jr.), Malibu's Most Wanted (with Rey Gallegos), and The Ladykillers (with Tzi Ma and Stephen Root).