The song sung by Hettie on the boardwalk is a variation of "Poor Wayfaring Stranger"
Kelsey Grammer is credited as a guest voice even though Sideshow Bob does nothing but grunt angrily while cleaning off Bart's graffiti.
On the wall in the NPR station there's an advertisement for a show called "Gross Air with Terry Fresh," a play on real NPR show "Fresh Air with Terry Gross."