Apparently one of the perks of singing at the President's campaign fundraisers is a ticket to the White House Correspondents' Dinner. 

Katy Perry, who provided entertainment for several of President Obama's campaign events last year, was one of the guests at the star-studded event in Washington on Saturday night.  It was her second major visit to the nation's capital this year, after attending the Inauguration with her ex-boyfriend John Mayer.  

Katy showed up for dinner at the Washington Hilton in a green-and-gold Giambattista Valli strapless dress, and tweeted that night that she'd "just witnessed our President deliver the funniest speech" she had ever heard.  

Conan O'Brien was chosen for roasting duties at Saturday's Correspondents' Dinner in Washington D.C.  

The late night host questioned why President Obama is often called "the coolest guy in the room," saying that he would get the title too if he was being compared to Chuck Hagle and John Kerry.  He also asked the President why he keeps sending supporters five e-mails a day asking for more donations.  Conan quipped, "You won! Do you have a gambling problem we don't know about?!"  The comedian even took a jab at the President's jobs record, commending him for the fact that since his second term "the number of Popes has doubled and the number of 'Tonight Show' hosts has tripled." 

But the press also got their fair share of humble pie from Conan.  He particularly took aim at CNN, asking why the network chose to replace Larry King with "one of the scheming footmen from 'Downton Abbey'" - referring to its new host Piers Morgan.  He added that the only people who watch CNN are "the people who clean the offices at CNN."  Conan also made an observation while surveying the room full of the media elite Saturday night, noticing that television news was no different than a high school cafeteria.  He said Fox was "the jocks," MSNBC are "the nerds," bloggers are "the goths," NPR is the "table for kids with peanut allergies," Al Jezeera is "the weird foreign exchange student nobody talks to," and print media is "the poor kid who died sophomore year in a car crash." 

South Korean rap sensation Psy also made an appearance at the event, as a guest of CBS News.  He performed at the annual White House Christmas special last year.  According to "Deadline," he was seated at the same table as "Homeland" star Claire Danes and Hannibal's" Hugh Dancy."