The 'I kissed a girl and diddled her skittle' era

Coming from a wholesome, Christian background, you have to wonder what moved Katy Perry to pen a track about macking the cherry chapstick off girls. Whether she's actually kissed girls is still up for debate, but according to Perry, it was ScarJo who inspired her hit song.

'I saw a picture of Scarlett Johansson' she told Steppin' Out magazine. 'I was with my boyfriend at the time, and I said to him, 'I'm not going to lie: If Scarlett Johansson walked into the room and wanted to make out with me, I would make out with her.''

The epiphany paid off and, in the summer of 2008, she found massive chart success with 'I Kissed a Girl,' which was released as the first single under her newly adopted name.