When the surrogacy procedure is explained to Stan, he dismisses it as science fiction, claiming "I thought I saw every episode of Star Trek", then emphasizes that he had not seen Star Trek: Deep Space Nine (1993). In fact, a story arc in season 4 centered around a surrogate pregnancy to explain actress Nana Visitor's pregnancy.
This is the first time that the flag in the front yard is seen either being raised or lowered.
When Stan tries to fight Greg and Terry, their dance routine and the music is from West Side Story, specifically when the Jets rumbled with the Sharks.