In the proud tradition of U.K. groups that have one massively popular single and then fade from memory even more quickly than they appeared come the Cheeky Girls, Gabriela and Monica Irimia. Identical twins born on Halloween in Transylvania, the Cheeky Girls spent their adolescence studying voice, ballet, and modern dance. Gabriela and Monica switched from aspiring dancers to aspiring pop stars when they auditioned for the British talent search show Popstars: The Rivals, where they sang an early version of the song that became their trademark: "The Cheeky Song (Touch My Bum),"...