Apple has announced that the iTunes Store has now sold more than three billion songs. The store debuted on April 28, 2003, and sold its one billionth song on February 22, 2006 — the two billionth song was sold prior to Steve Job’s keynote address from January. Its catalog currently features over five million songs, 550 television shows, and 500 movies. “We’d like to thank all of our customers who have contributed to this incredible…