The girl in Ike's class that can't decide which candidate to vote for is named Flora, after Florida, the state in the 2000 presidential election that kept recounting its votes.

Kyle: Dude, what is your little brother doing here?
Stan: Ike is starting his first day of kindergarten.
Kyle: But Isn't he only 3 years old?
Stan: Yeah but he's some kind of genius so he's getting advanced placement kindergarten.
Ike: I pooped my pants.

Mr. Garrison: Oh, great! Flora's undecided! Well, you're just gonna have to sit there, Flora, and think about it until you come up with an answer.

Bill Cosby/VSM471: And so, Eric. Now you see why we must destroooy your Trapper Keeper.
Cartman: You guys. Did I mention that it has a pencil sharpener and a crayon sharpener?
Stan: Cartman, it takes over the world and destroys all of humanity!
Cartman: What would you guys have me do, huh? Walk around with just a plain old Trapper Keeper, like Kyle's? Is that what you want?!?
Stan: Yes!

Kyle: But dude, check out my new Trapper Keeper! It has five different compartments for each subject in school. And it's all covered with pictures from Dawson's Creek.

Dawson's Creek was a teen-oriented drama series that aired on the WB network from 1998 - 2003.

Bill: My name is Bill. Bill Cosby.

Bill Cosby is a famous American comedian and actor.

Filmore: My aunt Wosie, Wosie O'Donnell.

Filmore is talking about actress/comedian/talk show host Rosie O'Donnell. Rosie is currently starring on the female-oriented daytime talk show, The View.

Kyle: I'm going to try and break you away from the computer, Cartman. I need to remove the CPU.
Cartman: I'm afraid I can't let you do that, Kyle.

The way Cartman speaks and responds in this scene is reminiscent of the computer HAL, from the film, 2001: A Space Odyssey (1968).

Mr. Garrison: Okay, children, let's take our seats. My name is Mr. Garrison. And I'm the new kindergarten teacher. I used to be the third grade teacher, but I had a little (makes air quotes) 'nervous breakdown' and went into the mountains where I lived off of (makes air quotes) 'rat carcasses.'

The "nervous breakdown" is a reference to the last episode, "4th Grade," when Ms. Choksondik found Mr. Garrison living like a hermit in a cave.

Bill: Ah... hello Eric. Can I be your human friend? I mean, friend?
Cartman: I don't know, dude. I'm not supposed to have any male friends that are over thirty. I kind of got screwed on that once.

Cartman is referring to the episode, "Cartman Joins NAMBLA," when the older friends he met were looking for more than just friendship.