In Germany, this episode was dedicated to Elisabeth Volkmann, who was the German voice actress for Marge since the very first season. This was the last episode she had completed before her death in July 2005.
Intellectual Homer, who has been killed by Serious Homer, has written on the floor in his own blood "Ontogeny recapitulates phylogeny". This is the famous statement of Ernst Haeckel's recapitulation theory about the similarity of the embryonic development of organisms to its evolutionary history.
When Bart is on the plane the pilot sounds like Comic Book Guy.
Although it gets Bart in trouble in reality some airlines do allow passengers to fly unaccompanied.