Billie Piper at the premiere of her film Scoop last yearBillie Piper was the name on everyone’s lips this weekend, when she made a surprise appearance in the Doctor Who season finale.Originally known for her teen pop career here in the UK (bops like Because We Want To, Honey To The Bee, Walk Of Life and, crucially, Day And Night have really stood the test of time), Billie made the transition to acting in the mid-2000s when she joined the cast of the Doctor Who revival as a new companion, Rose Tyler.As Rose’s story evolved, the character eventually transformed into different entities like Bad Wolf and, in an appearance almost a decade later, The Moment. Meanwhile, Billie’s acting career saw her leading the salacious Secret Diary