Pop superstar Katy Perry appeared on "Saturday Night Live" over the weekend for the second time, but this time Perry served as a host, rather than just the musical guest.  Perry follows such musicains as Justin Timberlake, Britney Spears, Elton John and a handful of others to perform both duties on the show.  Perry did not perform, handing over musical duties to Robyn, who has opened for her on tour in the past.  Check out Perry's opening monologue below.