Jason Alexander

Jason Alexander (born "Jay Greenspan", September 23, 1959, in Newark, New Jersey) was one of the stars of the award-winning television sitcom "Seinfeld". His character, the neurotic ne'er-do-well George Costanza, Jerry Seinfeld's best friend, was based in part on the show's creator, Larry David. He has also appeared in a number of movies, and done some work as a director.

More details are available here: http://uk.imdb.com/Name?Alexander,+Jason