Zach Braff has said that he worked on the script and that he "tweaked the dialog a little bit". He also claims to have written the ending "porch" sequence.
The initials "Z.B." can be found carved in the porch when Zach Braff's character Michael is sleeping in front of the house waiting for Jacinda Barrett's character Jenna.
Michael's staying on the front door for several days is reminiscent of the East German film 'Die (1973) Legende von Paul und Paula'(The Legend of Paul and Paula), where Paul is also camping in front of Paula's apartment in order to win her back.
It was rumored that Rachel Bilson called for a body double during the sex scenes because she was uncomfortable being nude in front of the camera. Although she did refuse to show her breasts on camera, she wore panties and did still complete the scene without any double.