Arnold's brand of computer is called "Purdy," and a producer is named "Joseph Purdy."
It's shown that Mr. Green's first name is Marty.
In "Phoebe Cheats," Phoebe wakes up and talks to the statue trophy she illegitimately won, and repeatedly changes from a blue sweater to a night grown and back again between shots.
In "Phoebe Cheats," when she's trying to write a poem, you see her from the side, reading the book. It flashes to the back and she's writing. Then when it goes back to the side, she's still reading.