Conversation so far:
what does Cosmo Kramer have to do with a coffee table book?
Kramer first thinks of the book in The Cigar Store Indian, although he later claims that he first had the idea when skiing.
what was Cosmo Kramer's book tour regarding?
Kramer starts his book tour with an appearance on Regis and Kathie Lee.
In what episode of Seinfeld did Cosmo Kramer's book tour emerge?
In The Opposite, Kramer starts his book tour.

Question: who else was in the episode?
Self-contained rewrite: who else besides Cosmo Kramer was in the episode about his book tour?