In the episode "From Where to Eternity," 3 o'clock is mentioned throughout the episode. In this episode, its mentioned twice in similar instances. Once by Tony while talking to Dr. Melfi, and another time by Dr. Melfi when talking to her therapist, Dr. Kupferberg.
The voiceover on the Mercedes TV commercial, which Tony watches before going to bed with Carmela and which makes him think of Gloria, is voiced by Joe Mantegna, who also voices mob boss Fat Tony on The Simpsons, as well as playing Joey Zaza in The Godfather Part III.
The song played during the ending credits is "The Captain," by Kasey Chambers.
When Tony tells Carmela to disinvite Ralphie and Ro for Thanksgiving Dinner, he references The Jetsons (1962), stating Ralph's not going to Mr. Spacely's house for dinner.
2 more obvious product placement examples in this episode: The Mercedes-Benz commercial and the Snapple that Johnny Sack was drinking.