What do you give the pop star who has everything?
In the case of Britney Spears it was the gift of a zeitgeisty dance lesson, presented by Ellen DeGeneres.
Tuesday saw DeGeneres welcome Spears and fellow "X Factor" judge Simon Cowell to her couch, and in keeping with protocol for the stunt-loving show, DeGeneres noticed that Britney had tweeted her appreciation for a Korean rapper named Psy.

