Light saber

Rose Tyler joked that the samurai at the Battle of Minatogawa could end up fighting with Light sabers if they found the alien tech from the Volsci ship. (COMIC: Return of the Volsci)

Behind the scenes
Light sabers are the weapons famously used in the Star Wars film series. The connection is only loosely made in-narrative when Ninth Doctor responds to Rose's comment by remarking that George Lucas is a genius.