Will Ferrell; George Lopez; musical guest Keith Urban.
Adam Brody; Chris Matthews (""Hardball with Chris Matthews""); musical group The Bravery.
Tom Cruise; chef Chandler Goff; singer Toby Keith.
Heather Locklear; John Leguizamo; Foo Fighters.
Paul Giamatti; bug man Ruud Kleinpaste; the Pussycat Dolls.
Hilary Duff; comic Jim Norton; musical group Kaiser Chiefs.
Animal expert Jarod Miller; Cedric the Entertainer (""The Honeymooners""); singer Dwight Yoakam.
Kathy & Paris Hilton; Duane ""Dog"" Chapman (""The Bounty Hunter""); musical guests John Scofield and John Mayer.
Lindsay Lohan (""Herbie: Fully Loaded""); actor Jeremy Piven; musical group The Backstreet Boys.
Attorney Tom Mesereau; Paul Teutel, Sr., Paul Teutel, Jr. & Mikey Teutel (""American Chopper""); singer Courtney Jaye.
Martin Lawrence; Keith Olbermann (""Countdown with Keith Olbermann""); musical group Sugar Ray.
Sinbad; actress Amber Tamblyn; performers from the documentary ""Rise.""
Dr. Phil McGraw; Ebert & Roeper; singer Kathleen Edwards.
Don Rickles; chef Bobby Flay; singer Tracy Bonham.
Arnold Schwarzenegger; Larry the Cable Guy; musical group Black Eyed Peas.
Michael Clarke Duncan; actress Ariel Gade; Ringo Starr.
Roseanne Barr; singer Bo Bice.
Jessica Alba; Earvin ""Magic"" Johnson; Cirque du Soleil's ""Zumanity.""
Owen Wilson; singer Kem.
Tom Arnold; DJ Qualls; Relient K.
Dakota Fanning; actor Terrence Howard; musical group Rascal Flatts.
Johnny Depp; Eva Mendes; musical group Shout Out Louds.
Scarlett Johansson