The background music playing at Mr. Burns' investor's conference is the intro to Elvis Presley's version of "C.C. Rider," the King's usual opening song in his '70s concerts.
Homer’s car during his hallucination as he’s getting ready for work looks like Benny the Cab from Who Framed Roger Rabbit.
When Marge is making the scarecrow for her vegetable patch, pop-ups appear on the screen in the style of VH1’s Pop-Up Video.
The song Phish is singing is "Run Like an Antelope". Later, Phish plays the opening limb of the Simpsons theme song, something Phish actually did in their real-life concerts.
When Homer smokes pot, he says that it (marijuana) can "make anything funny, even that show that follows Friends." This is possibly a reference to Frasier, which did follow Friends at the time of this episode's original air date but is more likely a reference to the numerous—and usually short-lived—series scheduled after Friends for many years.
In this episode Homer says "I could walk up to the president and blow smoke in his stupid monkey face, and he'd be sitting there groovin' on it" is a reference to former president George W. Bush, who was often mocked for having a simian-looking face and did drugs in his college days. The joke becomes very tasteless with Barack Obama (an African-American man) as the current president, since "monkey" is used as a racial slur for black people.
Because the episode dealt with marijuana smoking and getting it legalized this episode was given a TV-14 rating on American television. In the UK, this episode, due to the references to marijuana and scenes of Homer being abused by animals, this episode was initially banned, but later aired post-watershed (and never advertised). In Australia, the episode also only aired post-watershed and was given a higher rating than usual (the "M" rating, which was also used in "Natural Born Kissers" for sexual content, Treehouse of Horror XV for drug abuse, sexual content, and brutal violence, and "Million Dollar Abie" for references to animal abuse and assisted suicide).