You might think that Halloween costumes were no big deal for the stars, who get to dress up every day for their work. But you would be wrong. Here's a look at how some stars celebrated the holiday. Blake Lively from, "Gossip Girl," left, is dressed as Cleopatra and host Martha Stewart, dressed as Medusa, bake a cake on "The Martha Stewart Show," Oct. 31, 2008, in New York.
From left, comedian Kathy Griffin, actress Bette Midler and singer Gloria Estefan pose together at Midler's Halloween Benefit Gala for the New York Restoration Project at The Waldorf Astoria in New York on Friday, Oct. 31, 2008.
Regis Philbin, left, dressed as country singer Billy Ray Cyrus, and Kelly Ripa, dressed as his daughter Miley Cyrus, are shown during their annual Halloween extravaganza on "Live with Regis and Kelly," on Friday, Oct. 31, 2008, in New York.
Singer Patti Smyth and former tennis star John McEnroe arrive at the Halloween Benefit Gala for the New York Restoration Project at The Waldorf Astoria in New York on Friday, Oct. 31, 2008.
Model and television personality Heidi Klum, left, and her husband Seal attend her annual Halloween party at 1 Oak on Friday, Oct. 31, 2008 in New York.
Model and television personality Heidi Klum attends her annual Halloween party at 1Oak on Friday, Oct. 31, 2008 in New York.
TV personality Kim Kardashian, left, and her boyfriend, NFL player Reggie Bush, arrive for the Pur Jeans Halloween Bash in Los Angeles, Friday, Oct. 31, 2008.
Singer Pink attends Heidi Klum's annual Halloween party at 1 Oak on Friday, Oct. 31, 2008 in New York.
Lauren Conrad of "The Hills" looks back for photographers at the Pur Jeans Halloween Bash in Los Angeles, Friday, Oct. 31, 2008.
John Legend and his girlfriend, Chrissy Teigen, arrive for the Pur Jeans Halloween Bash in Los Angeles, Friday, Oct. 31, 2008.
Lo Bosworth arrives for the Pur Jeans Halloween Bash in Los Angeles, Friday, Oct. 31, 2008.
Khloe Kardashian, left, and her sister Kim Kardashian pose together at the Pur Jeans Halloween Bash in Los Angeles, Friday, Oct. 31, 2008.
NBC "Today" television program cast members, from left, Ann Curry, Al Roker, Meredith Vieira, Matt Lauer, Hoda Kotb, Kathie Lee Gifford and Amy Robach dress as fairy tale characters for their annual Halloween show, in New York's Rockefeller Center, Friday, Oct. 31, 2008.
Actor Ed Westwick shows off his Halloween costume which he said represented "a (typical) night out in 2008" at the Soho Grand Halloween Party sponsored by Dos Equis. "Gossip Girl" co-stars Chace Crawford and Jessica Szohr were also there.
Mena Suvari and her boyfriend pose in costume at the Soho Grand Halloween Party sponsored by Dos Equis.
Alexis Bledel, left, poses with Mena Suvari in their costumes at the Soho Grand Halloween Party sponsored by Dos Equis.
Dressed as firefighters, singer Nick Cannon and his wife, singer Mariah Carey, arrive by firetruck to her Halloween party at Marquee, Thursday, Oct. 30, 2008, in New York.
Actress Jamie Lee Curtis shows off her patriotic spirit at the Dream Halloween annual fundraiser for the Children Affected by AIDS Foundation, Saturday, Oct. 25, 2008, in Santa Monica, Calif.
Actress Jada Pinkett Smith and her daughter, Willow Smith, arrive at the Dream Halloween annual fundraiser for the Children Affected by AIDS Foundation, Saturday, Oct. 25, 2008, in Santa Monica, Calif.
Actress Melina Kanakaredes of "CSI: NY" is a witch, but not a scary one, at the Dream Halloween annual fundraiser for the Children Affected by AIDS Foundation, Saturday, Oct. 25, 2008, in Santa Monica, Calif.