(written from a Production point of view)
Acclaimed film and television director Bryan Singer (born 17 September 1965; age 51) made a cameo as Lieutenant Kelly in Star Trek Nemesis. A fan of Star Trek, he got the role due to his association with TNG star Patrick Stewart, whom he directed in the Marvel Comics film adaptation X-Men and its sequels X2 and X-Men: Days of Future Past. He also directed Famke Janssen and Bruce Davison in these films.
Born in New York City, Singer was adopted as a child and received a Jewish upbringing in New Jersey. After graduating from West Windsor-Plainsboro High School (South), he studied at the School of Visual Arts in Manhattan, New York, followed by the USC School of Cinematic Arts in Los Angeles, California. Openly gay, he has credited his experiences as a minority with influencing his work that followed.
Singer first gained attention for directing the highly-praised 1995 thriller The Usual Suspects, which featured Jack Shearer among its cast members. He went on to direct Apt Pupil, featuring Bruce Davison, before acquiring possibly his greatest fame with the first two X-Men films.
In 2005, Singer, The Usual Suspects writer Christopher McQuarrie and Robert Meyer Burnett discussed their own Star Trek TV show after the cancellation of Star Trek: Enterprise. The 25-page series proposal by Burnett and Geoffrey Thorne, Star Trek: Federation, was set in the year 3000 and in age of decline for the Federation. The plan was for Singer's Bad Harry Productions to produce the show, with a pilot written by McQuarrie and directed by Singer. Burnett would be executive producer. The pitch, completed in January 2006, was never given to CBS as Paramount had announced it was collaborating with J.J. Abrams on Star Trek.  Singer commented he would turn down directing a Star Trek film, stating he would be too "precious" with the universe. 
Singer chose to write, produce and direct Superman Returns instead of the third X-Men film, which became X-Men: The Last Stand. Both films were released in the summer of 2006. Superman Returns stars Star Trek: Deep Space Nine guest actor Frank Langella as Perry White, editor of the Daily Planet. The film did not gross enough to make a profit and to greenlight a sequel, and Singer moved on and reunited with McQuarrie to direct Valkyrie in 2008, starring Tom Cruise as Claus von Stauffenberg. Singer produced X-Men: First Class, a 2011 prequel to his X-Men films, and reunited with Stewart for the 2014 sequel, X-Men: Days of Future Past. The film includes a clip of William Shatner in "The Naked Time", referencing the time travel in the episode.
Singer's production company, Bad Hat Harry Productions, produced the hit TV series House, and he occasionally directed episodes for the series, including the pilot. Jennifer Morrison was a regular on the series, playing Dr. Allison Cameron. Singer also directed the 2013 fantasy adventure Jack the Giant Slayer.