Mariah and Nick, at NYC's M2 Ultra Lounge, knows that if you're going to do disco ball, and rock it, this is the one night of the year for it.
At Fox's 'Billboard's New Year's Eve Live' at Las Vegas' Mandalay Bay Beach, Carmen Electra perfected that specialty of New Jersey's real housewives: simultaneously trashy and dowdy!
And speaking of the RHoNJ, here's Danielle Staub, inexplicably hosting a Joonbug.com New Year's Eve 2010 Party at China Club in what appears to be a swirl of soft-serve.
The New York iteration - here's Kelly Killoren Bensimon - go, on the other hand, for the Miss Hannigan exposed-garters look.
At Vegas' Venetian, Christina Aguilera wore a slip.
Keri Hilson, at Miami's Karu & Y, channels the sun. Or the Statue of Liberty. Or Liza.
Also in Miami, Stacy Keibler, at the Fontainebleau Miami Beach, could, as we say in retail, "definitely size down."
Malan Breton, at NYC's China Club, owes a debt to the Oneders.
Nicole Richie, at the Venetian, looks adorably retro - in a festive, ball-dropping sort of way.
Sacha, at Fontainebleau Miami Beach, has been raiding Pagliacci's closet again.
Meanwhile, at Joe's Pub in New York, Sandra Bernhard reminded us that life is, always, a cabaret.
[Images via Getty]