Marilu Henner, actress and star of 'Taxi (1978)', has a cameo in the book-signing scene of this episode. Henner is one of the rare individuals who have actually been diagnosed with Hyperthymesia, the condition that is the basis of the lead character's superior memory.
In the first season of "Unforgettable", Kristen Bush had a guest part in the episode titled "Friended", playing a character named Laurel Harrison. She also played Annie Spellman in the episode "Unfriended" in the seventh season of "Elementary".