Ellen On 'Idol,' '90210' Day And J. Lo On 'HIMYM' Tops Today's Tweet Dreams

"American Idol" gets a new judge (and pair of dancing feet) when Ellen DeGeneres (pictured) makes her debut tonight. Actress Lucy Hale is no doubt on Team Ellen, posting, "Ellen on idol Tonight! I. Can't. Wait." Meanwhile, "AI" host Ryan Seacrest (who, according to "Modern Family" star Sofia Vergara, "smells delisioso") shared his conversation with Ellen about co-judge Simon Cowell, tweeting, " she said 'he's gonna be a challenge'...'we're both completely different people.'"

But, while America has "Idol," the UK and other foreign countries get bragging rights to "90210" as their calendar is marked 9-02-10. Tristan Wilds tweeted, "hahahah shout outs to Brazil, UK, Belgium, and anywhere else repping 9-02-10 day!!!!" as his costar Matt Lanter wrote to overseas followers, "It's been brought to my attention that it's national "90210 day in foreign countries( 09-02-10). Nice."

Keep reading to get the rest of today's best tweets from celebs, including the "Valentine's Day" premiere and Neil Patrick Harris dishing on Jennifer Lopez's upcoming appearance on "How I Met Your Mother." Be sure to follow us all week on Twitter (8,000 loyal followers and counting!) @Hollywoodcrush to get all the latest in movies, TV, music, and more!

@jason_mrazValentines Day in 5 days! (on a Sunday no less) Make plans to give away something great in the name of Love - for yourself and for others!
-Jason Mraz, Musician

@mariolopezextra Valentines Day premiere was awesome. The ladies looked beautiful. There was a big crowd that showed up.
-Mario Lopez, TV Host, Actor ("Extra," Saved By The Bell")

@robertsemma Had SO much fun at the premiere. LOVED the movie. You guys will love it too!! Can't wait until everyone sees it!!
-Emma Roberts, Actress ("Valentine's Day")

@joemanganiello Quality Problem: i might miss the WOLFMAN premiere tonight... because i'm playing a wolfman on TV...
-Joe Manganiello, Actor ("True Blood," "One Tree Hill")

@vanderjames For @jimmyfallon tonight, I'm thinking of dressing like Zack Morris & never breaking character... that's never been done, right?
-James Van Der Beek, Actor ("Dawson's Creek," "Mercy")

@actuallynph J LO's on HIMYM, not Glee. At least not yet. Future Ted Mosby got to her first! How bout that? Bang!
-Neil Patrick Harris, Actor ("How I Met Your Mother")

@stephaniepratt 7hrs of traveling was so fun thanks to The Office, Dear John and this blonde girl next to me (Lo). Happy to be home!!!
-Stephanie Pratt, Reality Star ("The Hills")

@mattmorris Headed to the Bluegrass Airport (I swear, that's what it's called) - very glad to be going home.
-Matt Morris, Musician

@danielcudmore Went an jumped around at open gymnastics last night, so much fun! Ok, hold off on the laughs...i'm a lot more agile then you would think!
-Daniel Cudmore, Actor ("New Moon," "Eclipse")

@emmyrossum No idea HOW it happened but I've got that beachy Giselle-hair thing going on 2day.I will cherish this,realizing it may never come again! Ha!
-Emmy Rossum, Actress ("The Phantom of the Opera")

@jessimtv Running with the Olympic torch in 2 hours. If I drop it, the WHOLE WORLD is let down. no pressure.
-Jessi Cruickshank, TV Host ("MTV Live")

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Tags 90210, American Idol, Ellen DeGeneres, Lucy Hale, Matt Lanter, Ryan Seacrest, Simon Cowell, Tristan Wilds, Tweet Dreams, Twitter