In I Second That Emotion, theres a scene where Fry goes into the sewer and we can see this manhole cover that says The PJs. This is a reference to the stop motion animated show The PJs created by Eddie Murphy, which briefly ran on Fox around the same time as Futurama. It didnt end up being nearly as successful as Futurama, but this was a fun little shout out that actually would come back in a later episode, The Luck Of The Fryrish.