Welcome back to Twitter, Demi Lovato! The singer-actress made her triumphant return to the social networking site on late Tuesday night after taking a break in November to enter rehab for emotional and physical issues. The Disney star had some good news to share when she posted, "Guess who's baaaaaaaack...!!!!!!!" Her excited followers, fans, and friends alike, welcomed Demi (pictured) back with open arms, including Kim Kardashian who told her, "OMG twitter has missed u soooo much!"
Elsewhere, if Kellan Lutz was hoping for scads of Twitter wishes on his birthday, it certainly looks as though his 26th was a very successful one. Kellan received a sweet tweet from his "Breaking Dawn" co-star Ashley Greene that read, "Happy happy birthday @kellanlutz love ya!!" as well as one from his pal, actor Ryan Rottman, who posted, "Happy Birthday to the man who created the infamous Dice game @kellanlutz!! Stay Classy."
Check out the rest of today's best celebrity tweets, including Kevin Williamson's welcome to Twitter newbie Paul Wesley and Justin Bieber introducing his wax figure to the world! Follow us @hollywoodcrush to get even more celebrity and pop culture news around the clock!
@justinbieber look right over there. they think we know eachother... http://plixi.com/p/84220549
-Justin Bieber, Singer
@kevwilliamson I'm up writing. What are you doing @paulwesley ????
-Kevin Williamson, Writer, Director ("The Vampire Diaries," "Scream 4")
@paulwesley hmmm.... i finally have succumbed to the lure of twitter... hello everyone 
-Paul Wesley, Actor ("The Vampire Diaries")
@msamberpriley Hi. My name is Amber Riley, and I'm a reality show junkie *hangs head, runs out room* lol
-Amber Riley, Actress ("Glee")
@aubreyoday Just caught up on the latest episode of Big Love... OMG, so Amazing!
-Aubrey O'Day, Reality Star ("All About Aubrey")
@ichadlowe Just finished directors cut of #Bones! Great group of people to work with! Now eager to start season 2 of #PLL! Also great people!
-Chad Lowe, Actor ("Pretty Little Liars")
@jessetyler Today @ericstonestreet did a perfectly executed pratfall in a scene. Meanwhile, I wrenched my neck holding lily and turning my head funny.
-Jesse Tyler Ferguson, Actor ("Modern Family")
@mintzplasse @JonahHill dude you're looking good!
-Christopher Mintz-Plasse, Actor ("Superbad," "Kick-Ass")
@mindykaling I'm on Letterman tonight, after Bradley Cooper! @edwardhelms you were the conversational lynchpin for me and BC! #thankspal
-Mindy Kaling, Writer, Actress ("The Office," "No Strings Attached")
@avrillavigne I'm doing @jimmykimmellive tonight!.... Well not literally hahahha ... Singing "What The Hell"... So check it out!
-Avril Lavigne, Singer
** Hollywood Crush Twitter