When Jill and Jimmy are having their make-up sex, we hear Bruce Willis saying "Yipee-ki-yay." This alludes to his famous catch-phrase in the 'Die Hard' movies.
The tattoo on Jimmy the Tulip's back is the logo of the production company.
Matthew Perry previously made a cameo in Howard Deutch's first film, Pretty in Pink (1986), as the kid in the record store.
The angry rant that Oz goes on to his assistant upon returning to his office near the end of the film is one continuous shot.