In the opening titles, it is said that the episode was written by 'The Lonely Donkey Kong' and 'Specialist Contagious'. These are, in fact, Damon Lindelof and Tom Perrotta, after they entered their name into the Wu Tang Name Generator. This connects to the tattoo in the episode.
To add to their "Perfect Strangers" joke, the episode's title, "Don't Be Ridiculous", is a catch phrase from Perfect Strangers.
As a joke, related to the appearance of Mark Linn Baker as himself and the conversation about Perfect Strangers, the show he starred in, the normal opening credits song ("Let the Mystery Be") was replaced by the Perfect Strangers theme song.
When Mark Linn-Baker is trying to convince Nora that he is serious, he tells her, "I have two degrees from Yale." This is true; the real Linn-Baker received his undergraduate degree from Yale in 1976 and an MFA from the Yale School of Drama in 1979.
The background music when Nora is in Missouri is the theme from Perfect Strangers.