http://en.wikipedia.org/wiki/The_Sneetches_and_Other_Stories"The Sneetches"
Sneetches are a group of vaguely avian yellow creatures who live on a beach. Some Sneetches have a green star on their bellies, and in the beginning of the story the presence or absence of a star is the basis for discrimination. Sneetches who have stars on their bellies are part of the "in crowd", while Sneetches without stars are shunned and consequently mopey.
In the story, a "fix-it-up chappie" named Sylvester McMonkey McBean appears, driving a cart of strange machines. He offers the Sneetches without stars a chance to have them by going through his Star-On machine, for three dollars. The treatment is instantly popular, but this upsets the original star-bellied Sneetches, as they are in danger of losing their method for discriminating between Sneetches. Then McBean tells them about his Star-Off machine, costing ten dollars. The Sneetches formerly with stars happily pay the money to have them removed in order to remain special.
However, McBean does not share the prejudices of the Sneetches, and allows the recently starred Sneetches through this machine as well. Ultimately this escalates, with the Sneetches running from one machine to the next,
"until neither the Plain nor the Star-Bellies knew
whether this one was that one or that one was this one
or which one was what one... or what one was who."
This continues until the Sneetches are penniless and McBean departs a rich man, amused by their folly. Despite his assertion that "you can't teach a Sneetch," the Sneetches learn from this experience that neither plain-belly nor star-belly Sneetches are superior, and they are able to get along and become friends.