The white haired man speaking to Phil (who also happens to be the father of Rhea Perlman) at the corner of the bar is Robert Alley, the father of Kirstie Alley.
In the final scene (at 21:05), there is a moment where Kirstie Alley is standing on the right talking to Rhea Perlman, who is standing on the left. Directly behind them at the end of the bar are their real life fathers: Philip Perlman, seated on the left, and Robert Alley, seated on the right. No one else is in the shot.
Rhea Perlman throws a drink into the face of her real life father, Philip Perlman.
Cliff calls Frasier's patients Wynken, Blynken, and Nod. "Wynken, Blynken, and Nod" is a popular poem for children written by American writer and poet Eugene Field. The poem is a fantasy bed-time story about three children sailing and fishing amongst the stars from a boat which is a wooden shoe. The little fishermen symbolize a sleepy child's blinking eyes and nodding head.
This episode aired January 2, within a week of Elvis Presley's actual birthday.