Zii Dance Dance Revolution is a parody of Wii Dance Dance Revolution.
As the Simpsons are entering the arboretum, one of the sculpted bushes they pass is "Binky", a character from Matt Groening's comic "Life in Hell." The other pair of bushes are Kang and Kodos, The Simpsons' resident space aliens.
Gil is seen with white hair
When Marge found Maggie missing, she was bringing her a glass bottle (it shatters when she drops it).
Fat Tony says he wants to take out the Castellaneta family; Dan Castellaneta is the voice of not only Homer, but several other people on the show.
Lionel Hutz is visible in the large panning crowd shot at the Botanical Gardens.
The shirt Moe is wearing at Maggie's birthday party is the one Marge gave him
This episode was written by J. Stewart Burns who won an Emmy for the Futurama episode "Roswell That Ends Well".
When Moe tries to get out some toys, which includes a Tickle Me Elmo. After he tests some other toys,he brings out a Tickle Me Elmo. But when he thinks he abused the Tickle Me Elmo,he said "You can't tickle Elmo no more", he made the Tickle Me Elmo say "No means no for Elmo." then Elmo slaps Moe.
The song played when Moe is spending time with Maggie (and over the pictures of Homer and the ham) is "You're My Best Friend" by Queen.