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She needs a hottie for that hat! Holly Madison livens up the party in – where else? – Las Vegas on Friday, leading a countdown at Lavo inside the Palazzo hotel.
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NOTHIN' LIKE HIM
Bruno Mars caps off his biggest year yet with a performance at the R Lounge in New York City's Renaissance Times Square Hotel.
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Whatever happened to a simple kiss? Nelly takes a nibble out of longtime love Ashanti while hosting a bash at Haze nightclub in Las Vegas.
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In Florida, Kourtney Kardashian lights the new year afire while hosting The Rooftop's party at the Gansevoort Miami Beach.
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Back from Barbados, Rihanna toasts the new year in Las Vegas with an orange cocktail while hosting the countdown at Pure Nightclub inside Caesars Palace.
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Kim Kardashian sparkles and shines as host of Tao Nightclub's New Year's Eve bash at The Venetian in Las Vegas.
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Mark Wahlberg and wife Rhea Durham make it a parents' night out at the private afterparty to wrap up the Jay-Z and Coldplay concert.
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Wearing a rainbow of colors, Nicki Minaj greets the new year with a big smile at Mansion nightclub Miami's South Beach. "HAPPY NEW YEAR my darlingzzz!!!!" she tweeted. "God bless you all with a prosperous 2011!!!!!! :-)"
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POW, POW, POW!
Usher comes on strong – and sweaty! – performing his OMG tour for thousands of fans Dec. 31 at Miami's American Airlines Arena, along with Trey Songz.
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Where's the ball? Alex Rodriguez is on Team Party while out at the Marquee bash hosted by Jay-Z. The star batter dropped into Vegas with Cameron Diaz, catching a show by Florence and the Machine together a night earlier.
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ON THE CLOCK
"Tik Tok" singer Ke$ha arrives to help Ryan Seacrest count the seconds to midnight in New York's Times Square. The popster performed her hit single – and vowed to make "2011 our b–" – on Dick Clark's New Year's Rockin' Eve.
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MAN OF THE HOUR
Dapper host Jamie Foxx takes the stage at LIV inside Miami Beach's Fontainebleau hotel, where Kaskade also performed.
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Celeb deejay Samantha Ronson takes the mic at the afterparty following the Jay-Z and Coldplay show.
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Surfer Kelly Slater and Jeremy Piven hug it out and hang ten at Jay-Z's private afterparty at Marquee.
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