(written from a Production point of view)
Thomas Baptist Morello (born 30 May 1964; age 57), better known simply as Tom Morello, is a Grammy Award-winning guitarist from Harlem, New York, who made two cameo appearances on Star Trek, first as an uncredited Son'a officer in Star Trek: Insurrection. As such, he was the subject of a short hidden special feature, aka "Easter egg", while he was filming his Insurrection scenes, which was included on the 2005 Star Trek: Insurrection (Special Edition) DVD.
In 1998, Morello – a die-hard Trekkie – contacted Star Trek producer Rick Berman and asked to have a cameo in Star Trek: Insurrection. Berman agreed, as his son was a fan of Rage Against the Machine. Despite four to five hours of make-up and the high temperature in which they were working (they were filming in the desert), Morello states that he "was on cloud nine because I got to talk to Jean-Luc Picard" (referring, of course, to actor Patrick Stewart). 
Because his Son'a character could barely be seen, however, Morello was asked to appear on an episode of Voyager, this time as a Human Starfleet officer, and as such appeared as Crewman Mitchell on the Star Trek: Voyager episode "Good Shepherd". In the latter appearance, Morello's Mitchell directs Voyager's captain Janeway, to junction room 16, "To the left, ma'am". After shooting the episode, "Good Shepherd", Morello was praised by Rick Berman, who stated "He [Morello] did a great job. It was a little pick-me-up for everyone." 
As a musician, Morello may best be known as founding member and lead guitarist of the alternative/hard rock band Rage Against the Machine, whose hits include "Bulls on Parade", "Guerrilla Radio", and "Sleep Now in the Fire". After the band split up in 2000, Morello and fellow Rage Against the Machine members Tim Commerford and Brad Wilk joined singer, songwriter and guitarist Chris Cornell (formerly of the band Soundgarden) to form another highly successful and popular music group, Audioslave, who had hits with "Like a Stone", "Doesn't Remind Me", and "Be Yourself", among others. In 2007, Audioslave disbanded and Morello, Commerford, and Wilk reunited with singer Zack de la Rocha to reform Rage Against the Machine.
In his capacity as guitarist for Rage Against the Machine, Morello had Voyager star Garrett Wang appear briefly in their video for "Sleep Now in the Fire." Wang is seen enjoying the music at about 2 minutes and 10 seconds into the video.
Morello has shared two Grammy Award wins and another four nominations with his Rage Against the Machine bandmates. He also shared a Grammy nomination as a member of Audioslave. Rolling Stone magazine ranked Morello as #26 in their list of "100 Greatest Guitarists of All Time".  In addition to his band affiliations, he also performs acoustic folk protest songs under the name The Nightwatchman.
Following his stints on Star Trek, Morello had a role in Jon Favreau's 2001 comic film Made, co-starring Star Trek: The Next Generation guest actress Famke Janssen. Favreau later cast Morello in a cameo in the 2008 Paramount Pictures release Iron Man, which co-starred Faran Tahir. Morello also had a supporting role in the 2005 independent drama Berkeley, along with Tracey Walter. In addition, Morello performed guitar for the films xXx: State of the Union, Talladega Nights: The Ballad of Ricky Bobby, and Iron Man and his music can be heard in such films as The Matrix, Dodgeball: A True Underdog Story, and Collateral.