Donna tells Josh, "Gather ye rosebuds while ye may", which is a quote from the poem "To the Virgins, to Make Much of Time" by Robert Herrick. That quote becomes a major plot point in the series The Newsroom, another Aaron Sorkin show.
During a party Donna walks away from Josh to "Go stalk Matthew Perry ". Matthew Perry goes on to appear in episode 20 of season 4. He also appears in Aaron Sorkin's later TV show 'Studio 60 on the Sunset Strip' with Bradley Whitford who plays Josh Lyman.
Portions of the party were shot at the headquarters of the Daughters of the American Revolution (DAR) in Washington DC.
C.J. gets approached at the party with an offer to be head of development at a production company and says she doesn't know what that is and never gets an explanation. Development, in film production, is the stage where the producers come up with an idea for a movie (book adaptation, true story, original story, etc.) and then get to work on getting the copyrights/licenses to make the movie, write the screenplay, and secure financing for the project.
In this episode Jorja Fox appears as Zoey (Elisabeth Moss)'s Secret Service agent, although her name is mispelled on the credits she is listed as Jorjan Fox.