Justin Bieber And Ke$ha Celebrate Birthdays In Today's Tweet Dreams

Oh, Crushers, our little Biebs is growing up! *sniff* Yes, Justin Bieber (pictured) is celebrating his 17th birthday today, and there was certainly no shortage of well-wishes from his celebrity pals around the Twitterverse. Usher posted to his protege, "Happy Birthday Lil Bro...JB I love you and hope you are enjoyin' your BIG 17th" as P. Diddy told him, "Happy Birthday to my little brother @justinbieber #happy17thbdaybiebs - love you boy." Even Justin's extended entourage, the guys from "Jersey Shore" made sure to tweet him some birthday love, including The Situation, who asked, "HEY DID EVERYONE WISH @justinbieber A HAPPY BIRTHDAY? HAPPY BDAY JUSTIN FROM ME & #SituationNation" while DJ Pauly D wrote, "Happy Birthday To My Homie @Justinbieber ..... #neversaynever." All the wishes seemed to help Justin have a great start to his 17th year, as he shared with friends and followers, "thank you for an incredible bday!"

Turns out the Biebs isn't alone in celebrating a birthday on March 1st! The one and only Ke$ha turns 24 today and got her fair share of bday wishes from famous friends too. Katy Perry (who celebrated her own milestone today, "#6millionfollowers?! THANKS! I ?") tweeted to her fellow songstress, "HAPPY BIRTHDAY CRAZY GAL! ?" and Adam Lambert made sure to tell the "Tik Tok" singer, "Happy Birthday @keshasuxx ! Miss you!"

Check out the rest of Tuesday's best tweets from the stars, including Ciara gearing up for a stint on "Hellcats" and Pink sharing her feelings on the latest Christina Aguilera controversy! Follow us @hollywoodcrush to get even more celebrity and pop culture news around the clock!

@theellenshow This morning I got surprised in my office by Colin Firth. He also brought his new friend, Oscar. http://ellen.tv/ehCEQD

-Ellen DeGeneres, TV Host ("The Ellen DeGeneres Show")

@ijennaush Hi ho hi ho off to the gym I go.. then to McKinley High for the rest of the day..

-Jenna Ushkowitz, Actress ("Glee")

@ciara 1st time in Vancouver Canada! Excited to be shooting on the tv show Hellcats! Yay

-Ciara, Singer

@danielcudmore Hope everyone on BD is enjoying the beauty of Canada!

-Daniel Cudmore, Actor ("Breaking Dawn," "New Moon")

@mariahcarey Countdown to the baby shower! LYM!!! http://twitpic.com/453u6f

-Mariah Carey, Singer

@pink Out of Myself, Britney, and Christina- didn't everyone think I was gonna be the troublemaker? LOOK MA!!! No CUFFS!!!

-Pink, Singer

@emmyrossum Turns out today is my 2nd anniversary on twitter? Wow. Two whole years of exposing-the-inner-thoughts-&-public-display-of-brian-vommiting.

-Emmy Rossum, Actress ("Shameless," "The Phantom of the Opera")

@michellebranch Today is national pancake day! Am I the only person who wants to put a plain buttermilk pancake on their face?

-Michelle Branch, Singer

@jakewhetter What? It's National Peanut Butter Lovers Day??????? EXCUSE ME? Why was I not informed. This should be a national holiday!

-Jake Whetter, Radio Personality (Radio Disney)

@maggieq I want to bottle the smell of a book for people to spray on their kindles and ipads.

-Maggie Q, Actress ("Nikita")