As the clock ticked over into 2010, celebs around the world partied like it was 1999 - and then some!

Even though Twitter has been around for several years, this was the first time that we've celebrated New Year's Eve since Hollywood stars began truly embracing social media.

The glitterati was out in force last night, tweeting photos and messages from their A-list parties, night clubs and dinner parties.

Hugh Hefner stayed up well past his usual bed time to ring in the new year, tweeting, "It was a perfect New Year's Eve party - with new friends&old. And now to bed. Happy New Year from all of us at the Playboy Mansion!!!"

PerezHilton After-after hours party in my room. Alone! Listening to Finally by Cece Peniston. Smiling from ear to ear at my great night and great life!

IMKristenBell Today a bee stung me inside my ear. for real. as he did it he whispered "happy new year". just joking.

LudaJuice Happy new years! I'm in Miami partying every f*ckin where!!!!!

ShannonElizab Happy New Year everyone - hope you were all safe&had a perfect transition into our next decade! Happy 2010! Lots of love&success 2 all!!!

Elizabeth Banks Happy New Year! Bon Chance! L'chaim! Salud! Feliz Spanish!

petewentz Happy new year to the people that dope up on happiness.

ToriandDean Our dinner turned out amazing! I'll post all the pics tomorrow.. Happy New Year!

Nicky Hilton Happy New Years!!!!