Shortly after David Abbott (Mark Ruffalo) moves into his new San Francisco digs, he has an unwelcome visitor on his hands: winsome Elizabeth Martinson (Reese Witherspoon), who asserts that the apartment is hers — and promptly vanishes. When she starts appearing and disappearing at will, David thinks she’s a ghost, while Elizabeth is convinced she’s alive. Their quest for the truth ultimately leads to love in this spectral romantic comedy.
Mark Stephen Waters (born June 30, 1964) is an American film director and producer. Waters is perhaps best known for directing Mean Girls.
He is the brother of screenwriter Daniel Waters and has been married to actress Dina Spybey since 2000. He is a graduate of the American Film Institute and as of September 2006 has a development deal with Paramount pictures. He often directs light-hearted, family-friendly films. He has a daughter named Zoe.
Waters was one of the 120 invitees to join the Academy of Motion Picture Arts and Sciences in 2006. —Wikipedia