S.P.E.W. (Society for the Promotion of Elvish Welfare) was an organization created by Hermione Granger during the fourth year of her education at Hogwarts School of Witchcraft and Wizardry. (Harry Potter and the Return of James T. Kirk)
Also, something happened during S.P.E.W.'s existence that caused some embarrassment to Hermione, as Ron Weasley continued to tease Hermione about the group, even during their time aboard the USS Enterprise-A.