John Lennon telling Ronald Reagan about peace is a paraphrase of a real Lennon quote: "If someone thinks that peace and love are just a cliche that must have been left behind in the 60s, that's a problem. Peace and love are eternal."
Ed Baldwin's board shows how much the Space Shuttle program has advanced in the alternate timeline, allocating crew to mission STS-83. In the real world, STS-83 did not occur until 1997.
The cell phone used by Tracy Stevens is the IBM Simon; an early attempt at creating a "smartphone" from the mid 1990's. As with many technologies portrayed on the show, it is implied that cell phones advanced at a more rapid pace than in real life due to the space program.
With the help of doctors and dietitians, Michael Dorman gained 40 pounds to play an out-of-shape Gordo Stevens this season. He managed to do it quickly but found the weight gain affected his thoughts, emotions and sleep patterns. He managed to shed the weight in six weeks after filming finished.
In the bar, after Gordo's game of Asteroids is over, Ed has the top score (2,180,530), but Gordo is in the high-score list 6 times: 2,165,820, 2,137460, 2,091,420, 2,0623,890, 2,037,400 and 2,09,110. These give him high score numbers 2, 3, 5, 7, 8 and 10.