A headstone shows Kenneth's date of birth as May 27, 1781.
When Pete speaks poorly he is spoofing the incident with news reporter Serene Branson when she could not speak during a live broadcast.
When Jack and Liz duck into the NBC Store, there's a cardboard cutout in the background of the character Dwight Schrute from The Office (2005).
Frank's trucker hats say "Sitting Ovation" and - on a tiny hat worn underneath the regular one - "I Give Up".