Ellen can't get enough of PARIS HILTON! Paris is always up for having fun -- she's gone clubbing with Ellen, was dropped in the dunk tank on the show, and was even Ellen's 12 Days of Giveaways mascot! She's stopping by today and bringing a special guest: her mother, KATHY HILTON! The two have worked hard to raise awareness of Multiple Sclerosis, and will share what they're doing today and how you can participate. Then, everybody is talking about Know or Go! It's Ellen's favorite game that's taken the country by storm! Three more brave audience members are stepping up to play. They'll wish they'd studied their trivia, because if they don't know the answers, they GO! Also, many people were shocked when KATIE STEVENS was voted off "American Idol," and today she's here to tell Ellen everything that happened -- and what she really thinks about Simon!