Letterman: Following last week’s showbiz appearances by Ricky Gervais, Mike Myers and the hilarious Don Rickles, the upcoming week’s shows have more of a political angle. Next week sees ex-New York mayor Rudolph Giuliani drop by (on Monday), and Al Gore (on Thursday). Leno: American Idol judge Simon Cowell pops in (on Monday) along with Maroon 5, the winner of American Idol (on Thursday) and – some politics on Leno as well – governor of California, Arnold Schwarzenegger, will be on the show (on Wednesday). Conan: The always entertaining Amy Sedaris comes in for some laughs (on Tuesday) and Mike Myers is on to promote Shrek The Third (on Friday). The Daily Show: Al Gore also pops up on The Daily Show (on Thursday – the same day he appears on Letterman) to discuss the Presidential race.