Director Quentin Tarantino; Lenny Kravitz performs.
Actress Carmen Electra; actor/comic Charlie Murphy; Houston performs with Nate Dogg and Chingy.
TV/radio personality Adam Carolla; actor Jon Heder; comic Morgan Murphy.
Actor/comic Rodney Dangerfield; David Nkrumah Liebe Hart in the future talent showcase.
Actor Luke Perry; TV host Graham Norton (``Graham Norton Effect''); Paris Texas performs.
Actress Julie Delpy; actor/comic Sacha Baron Cohen; Incubus performs.
Actor Seth Green; actress Merrin Dungey; Akon performs.
Actor Paul Sorvino; actress Blanchard Ryan; Carole King performs.
Actor Matthew Lillard; ``The Amazing Race 5'' team of Charla and Mirna; the Dresden Dolls perform.
Sports commentator Mary Lou Retton; the Libertines perform.
Actress Debi Mazur; actor/comic Bruce Vilanch; Jack Johnson, G Love and Donavon Frankenreiter perform.
Actor David Alan Grier; actor Scott Baio; Matisyahu performs.
Actor Aaron Eckhart; comic Jim Florentine; Kay and Sarah Glynn.
Actor Josh Hartnett; actress Sarah Chalke; the Cure performs.
Comic Dane Cook; Trainwreck performs, featuring Kyle Gass of Tenacious D and Kevin Weisman of ``Alias.''
Actor/comic David Alan Grier; TV personalities Mose and Ariel (``Amish in the City''); Al Jarreau performs.
TV personality Pat O'Brien (``The Insider''); actress Rose Byrne; Tim McGraw performs.
Actor Jim Belushi; Jason Mraz performs.
Actor Josh Duhamel; NFL Hall of Famer Terry Bradshaw; Ozomatli performs.
Actress Farrah Fawcett; actor/comic Orlando Jones; Flogging Molly performs.
Actress Cheryl Hines; Jill Scott performs.
Sports commentators Al Michaels and Frank Gifford; Talib Kweli performs.
Actress Angela Bassett; actress Amanda Bynes; comic Maria Bamford.
Actor Charlie Sheen; Olympic softball gold-medalist Jennie Finch; Young Buck performs.
Musician LL Cool J; rap artist Flava Flav (``The Surreal Life'').
Actor Jeff Foxworthy; actor Matthew Fox; 8 Ball & MJG perform.
Actor John C. Reilly; actress Sherri Shepherd; rapper Kenny ``KT'' Tate.
Actress/author Pamela Anderson; Ying Yang Twins perform; Lou Rawls performs.
Actor George Lopez; Dallas Mavericks owner Mark Cuban (``The Benefactor''); Van Hunt performs.
Actor Dennis Franz; actress Ali Landry; the Used perform.
Actor Jerry O'Connell; football player Keyshawn Johnson; comic Ted Alexandro.
Actor Joe Mantegna; fisherman Byron Velvick (``The Bachelor''); the Scissor Sisters perform.
Actress Marcia Cross; comic Steve Harvey; Senses Fail performs.
Comic/author Wanda Sykes; TV personality Kristin (``Laguna Beach''); singer/songwriter Dr. Franklin Ruehl.
Actor John Goodman; actor Sean Faris; Korn performs.
Talent manager Bernie Brillstein; Jamie Cullum performs.
Actor/comic David Cross; actress Eva Longoria; Michael Tolcher performs.
Actor/comic Jeff Ross; future talent showcase featuring Larry Fischer.
Actress Kelly Osbourne; pro football player Terrell Owens; Supergrass performs.
Actor Dean Cain; actress Evangeline Lilly; comic Jerry Minor.
Actress Kelly Preston; journalist Anderson Cooper; Mos Def performs.
Actor Rupert Everett; Jem performs.
Actor Andy Dick; WWE wrestler Randy Orton; Breaking Benjamins perform.
Actor Billy Bob Thornton; actor Dominic Monaghan; pitcher Pedro Martinez's lucky charm, Nelson de la Rosa.
Model Brooke Burke; Tears for Fears performs.
Actor/comic Patton Oswalt; Bowling for Soup performs.
Actor/comic Drew Carey; TV personality Richard Branson (``The Rebel Billionaire''); Benjy Greenberg in the future talent showcase.
Actress Sara Rue; Elvis Costello and the Imposters perform.
Creator/directors Matt Stone and Trey Parker (``Team America''); actress Kristen Bell; Jimmy Eat World performs.
Actor Jason Schwartzman; rap artist/TV host Xzibit (``Pimp My Ride''); the Donnas perform.
Actor Blair Underwood; actress Virginia Madsen; Interpol performs.
Actor Joe Pantoliano; actress Regina King; Alterbridge performs.
TV/radio host Adam Carolla; actress Tisha Campbell Martin; comic Brendon Walsh.
Actor David Alan Grier; actress Kimberly Williams-Paisley.
Actress Shannen Doherty; former NBA coach Phil Jackson; Boston Red Sox player David Ortiz; the Pussycat Dolls perform.
Actor Adam Brody; TV personality Ben Stein.
Actor Wilmer Valderrama; actor Thomas Haden Church; Wyclef Jean performs.
Actor Zach Braff; tennis player Serena Williams; the Shins perform.
Actor Rhys Ifans; Rilo Kiley performs.
Actress Jennifer Tilly; producer Jerry Bruckheimer; Fabolous performs.
Actor James Garner; actor Peter Gallagher; comic Freddy Lockhart; a family from ``Wife Swap.''
Singer Bobby Brown; TV producer Dick Clark.
