Lightsaber

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 the Ninth Doctor responds to Rose's comment by remarking that George Lucas is a genius.