Well, at least that's the New York "urban legend" version of the story. Go to the "history of pizza" Internet site at http://www.ghgcorp.com/coyej/history.htm for the truth about pizza. There you can learn that the first true pizzeria was opened at Via Port'Alba 18 in Naples -- until then pizza was made at home or was only one item on varied restaurant menus. You can also learn how, in 1899, Raffaele Esposito modified the already centuries old Neapolitan pizza alla marinara by adding mozzarella and basil to make a patriotic statement (green basil, white cheese, and red tomatoes) when King Umberto I and Queen Margherita visited Naples. So Pizza Margherita was named after the same lady as Palazzo Margherita, the building that houses the American Embassy in Rome.
Learn about authentic Neapolitan pizza (there are rules!) at the Internet site of the Verace Pizza Napolitana Association: http://www.verapizzanapoletana.org/verapizza/inglese/index_English.html.
For some amazing pizza facts, go to: http://www.mazzios.com/html/k_facts.htm.
For some good authentic recipes: http://milioni.com/ricingl/tipi/8.htm.