Heidi Klum wins again. Klum did some freelance marketing for Johnny Knoxville's "Bad Grandpa" on the way in to her annual Halloween party. It was at Marquee in NYC this year. (Photo by Mike Coppola/Getty Images.)
Russell Simmons, at the Treats! Magazine party at No Vacancy, goes all the way back to the beginning, when he was promoting his younger brother's upstart rap group, Run DMC.
Derek Hough fared better than his sister in Halloween etiquette.
Aaron Paul took off his JFK mask for Ryan Seacrest at Treats where the cinnamon flavored Jose Curevo Cinge was flowing. Paul's cover was already blown when the Daily Mail posted photos of him emerging from Aahs! two days earlier with the plastic face in hand.
Sophie Summer, who holds a rare reality crown as appearing on both "Britain's Next Top Model" and "America's Next Top Model," reminded everyone at the Treats party that she's professionally attractive.
Chicago native Jeremy Piven channeled Al Capone. At one point, Ari Emanuel's current assistant approached Piven to share the "Entourage"/Ari connection. (Treats Magazine party photos by the talented Todd Williamson/Invision.)
This is not a costume. Perez Hilton on New Year's Eve 2008 and Thursday night as the punctuation mark on his transformation - the abs. Hilton hit Klum's party in New York. (Photos by Bryan Bedder and Cindy Ord for Getty Images)
Manager/producer/vampire Desiree Gruber, Klum, and NBC reality VP Brandon Riegg at Klum's.
Not bad, Bethenny Frankel. Frankel drew photographer Seth Browarnik's attention (background) at Klum's bash, while Klum drew Svedka, Smartwater, and Shutterfly as brand sponsors this year. (Photo by Mike Coppola/Getty Images.)
Jason Sudeikis supports the USA Track & Field Team, Olivia Wilde, and writer Pete Huyck (no mask?) at UNICEF's first Masquerade Ball at Hollywood Forever on Wednesday night.
NBC's upcoming "About a Boy" lead Dave Walton and pregnant Majandra Delfino, together expecting their second child, at UNICEF.
In downtown L.A., an indoor skatepark dressed up as a "runway" for French label Kenzo's "Kalifornia" bag launch. Fergie and creative director Humberto Leon had their dinner plates and Belvedere cocktails cleared before a female skateboard team Bart-Simpson'ed across the dinner tables. (Photo by Donato Sardella/Wireimage.)
Shenae Grimes, Jenna Ushkowitz, host George Kotsiopoulos, and Christina Milian held down the vip table at Midori's Annual "Green Halloween" party at Bootsy Bellows.
Brooklyn Crew: (Backrow) Madonna's son Rocco, hitmaker Swizz Beatz, and Knick's star Carmelo Anthony (the night before his season began) at a kids party in the hot borough thrown by hatmaker Flipeez. (Photo by Michael Stewart/Getty Images )
Larry David figured out how to never get caught in an awkward conversation. The "Curb" mastermind hit Casamigos Halloween Party in Beverly Hills on Friday night.
Nearby, Rande Gerber and Cindy Crawford inspired a resolution to a decades-long rock feud at the Casamigos party at real estate developer Mike Meldman's house.
WME Co-CEO Patrick Whitesell and Lauren Sanchez channel "Talladega Nights: The Legend of Ricky Bobby." For those keeping score, that film's John C. Reilly and Sacha Baron Cohen (but not Will Ferrell) are WME clients.
Alessanda Ambrosio lit up the party. What did you expect?
Ironic costume from Ryan Seacrest, the ubiquitous media personality who is anything but a phantom.
Cuba Gooding Jr. dressed as a party-pooper, as did Chelsea Handler, at Casamigos.
"Revenge's" Ashley Madekwe and Iddo Goldberg. (Meldman Photos by Jerod Harris/Getty Images.)
Matthew Morrison's annual Halloween/Birthday mashup moved to the Warwick on Saturday, where Jimmy Fallon hosted his post-Emmys party. Jennifer Morrison, JC Chasez, and the man at the center of the scene: Matthew "Andy Warhol" Morrison.
At Morrison's bash, Jesse Tyler Ferguson and Justin Mitka prove more popular than Affleck.
Kristin Chenoweth and producer Dana Brunetti, who deserved a party after recasting "50 Shades of Grey" last week.
What was clockwork in 2007 is now a rarity: Lauren Conrad making a nightlife outing. Fellow guest-stars on the party season - the band from Cafe Wha? in NYC's West Village who performed at the Dos Equis hosted party.
The "Glee" crew had one of its first festive gatherings since the death of Cory Monteith: Chris Colfer and Ashley Fink.
For the trick-or-treater demographic, Rachel Crow performed inside the transformed Barker Hangar at the Dream Halloween on Saturday, Keep a Child Alive's annual celebration.
Costume Anxiety: When the 7-time Oscar Winner for makeup throws a Halloween party, cut corners on your costume at your own peril. Kelly Osbourne with makeup A-lister Rick Baker at his "Monster Mash" on October 19.
Even when borrowing Ozzy's devil horns, Slash still fit them under his top hat. The Hudsons: Slash and Perla.
Jason and Naomi Priestly flip the calendar to November early: Dia de los Muertos.
"Saving Mr. Banks" star Victoria Summer at Baker's bash at Cinovation studios.
Baker, who has a line with MAC Cosmetics, had extra models showing off his handiwork. (Baker's Monster Mash photos by Wireimage.)
The fairy godmother....of retail? Martha Stewart and Hal Sparks grace the kids and families at the HUB Network's First Annual Halloween Bash at Barker Hangar.
What's up doc: Keenan Thompson, "Modern Family" kiddo Nolan Gould, and "The Conjuring's" Joey King on stage.
After suffering an early boot from "Dancing with the Stars", the perpetually costumed Bill Nye had time for Katherine McNamera and her tiny hat. The special airs on Saturday, October 26.
The HUB Club: The Mountie, Dan Pimentel (HUB's CFO/COO); the bullfighter Ted Biaselli (Programming VP); The-Boss-Doesn't-Wear-Costumes, Margaret Loesh (HUB President & CEO); Martha Stewart; draculette Dena Kaplan (HUB's Marketing Chief), and mouse Nikki Reed (Programming and Development VP).