While discussing Luke's apparent lack of female companions, Lorelai jokes: "Maybe he has a secret life. Maybe he's got a little chippy stowed away in Mount Pilot."
That is a reference to the fictional town of "Mount Pilot", which is often mentioned by the characters on "The Andy Griffith Show", a popular sitcom from the '60s.
Paris talks about the Puffs, a secret sorority at Chilton, including how powerful a member Sandra Day O'Connor had been. Actually, while she did leave home for most of her schooling, she didn't go as far from her parents' Arizona ranch as Connecticut. Miss Day attended the Radford School for Girls and Stephen F. Austin High School, both in El Paso, TX.
Lorelai says snicklefritz when talking about Chiltons head master. This is the second time she says it in the series. It is later used in the movie Pineapple Express (possibly as an homage to the show).
Brenda Strong, who plays Eva, & Emily Bergl, who plays Francie, both went on to Desperate Housewives (2004), portraying Mary Alice Young and Beth Young, respectively. Both characters were married to Paul Young at different points in the show. Both characters also committed suicide.
Both Brenda Strong and Lauren Graham have appeared opposite Peter Krause on television series - Strong as Casey McCall's love interest Sally Strasser on Sports Night (1998) and Graham as Adam Braverman's sister Sarah on Parenthood (2010).