As the song, "With or Without You" by U2 plays at the bar, Ross tells Chloe he likes the song. It is the same song he dedicated to Rachel on the radio in The One with the List (1995).
When Ross takes the picnic to Rachel's office and sets fire to her desk, she says to the person she is on the phone with, "I have Shemp in my office." This is a reference to Shemp Howard, one of the Three Stooges.
While it was long debated whether Ross and Rachel were actually on a break from their relationship when Ross had sex with another woman in Season 3, the show's producers and Jennifer Aniston have made it clear that when Ross screamed "WE WERE ON A BREAK!", he was...completely telling the truth.
The diplomat Sergei (Jim Pirri) who Phoebe goes on a date with is best known for his role as Tori Vega's father on the Nickelodeon sitcom Victorious.
Angela Featherstone, who plays Chloe, is in The Wedding Singer (1998) along with Christina Pickles, who plays Ross and Monica's mom, Judy Geller.