When Sandy Kominsky has his acting performance nightmare, he has the voice of Gilbert Gottfried and says, "Aflac", an insurance company famously known for his voice in commercials.
Martin raves about Super Panavision, but can't explain what it is. For the record, it's a camera that shoots with 65mm film stock, which is then printed in 70mm for release (the extra 5mm is for the soundtrack). It uses a regular lens; when an anamorphic lens is used, providing an even wider picture, it's Ultra Panavision.
In this episode Kathleen Turner talks/jokes about her ex-husband's funeral and has the line "I wouldn't miss it for the world". It's the same line she has in Friends when she gets invited to her son's wedding.