Royal Wedding Reactions. While many of us here in the United States were sleeping soundly, Prince William and his lady Kate Middleton were getting hitched at Westminster Abbey. It seems that the whole world is obsessed with the royal wedding, and celebrities are no exception. Click through to see which stars have been tweeting up a storm about the wedding of the century.

Paris Hilton
"What did everyone think of the Royal Wedding? Kate looked stunning in her beautiful gown. What an incredible wedding!" -- Paris Hilton, who is clearly impressed with British decadence
Joan Rivers
"Excited for the royal wedding! Prince William won’t wear a wedding band and Kate doesn’t care. The ring that matters is the one on his head." -- Joan Rivers, arguing that Prince William doesn't need to wear a ring as long as he put a ring on Kate's hand
Brooklyn Decker
"I cry at weddings every single time... Never fails. Kate!! and her father!!! Her sister!!! Tears!!!" -- Brooklyn Decker, who has a soft spot for sappy wedding stuff
Denise Richards
"Couldn't sleep last night...ended up watching the wedding. @torianddean should've just joined u anyway..gorgeous wedding...#RoyalWedding: -- Denise Richards, who wishes she had joined Tori Spelling's all-night royal wedding sleepover
Kirstie Alley
"Prince Harry is where it's at ladies ..."the naughty one" go get him!!!" -- Kirstie Alley, revealing her cougar-sized crush on Prince Harry
Kelly Cutrone
"God Saved the Queen BUT Kate saved McQueen" -- Kelly Cutrone, giving Kate Middleton props for walking down the aisle in Alexander McQueen
Judd Apatow
"Oh my gosh!! William and Harry are in the car. Leslie flew to England to see it and is now watching in the hotel room. Better on UK tv." -- Judd Apatow, who is not one bit jealous that his wifey is mere miles from the royal wedding.
Justin Bieber
"Congrats to William and Kate ...and Kate's sister. She was a hit with @thatrygood" -- Justin Bieber, who we think just might have a slight crush on Pippa Middleton.
Rachel Zoe
"So happy for the brilliant Sarah Burton! Kate Middleton looked beautiful - a true dream in McQueen!! XoRZ" -- Rachel Zoe, who gives her stylist tweet of approval to Kate's Alexander McQueen wedding dress.
Piers Morgan
"Prince Harry and Pippa Middleton - anyone else thinking what I'm thinking?" -- Piers Morgan, stirring up the romance rumor pot
Melissa Joan Hart
"Is Harry more decorated than Will in the military? Does anyone know? #RoyalWedding" -- Melissa Joan Hart, asking the tough questions via Twitter
Rainn Wilson
"Americans invited to Royal Wedding: Queen Latifah, Lady Gaga, Prince, Larry King and Steve Earle. #royalwedding" -- Rainn Wilson, highlighting the differences between American and British royalty
Simon Pegg
"I s**t you not, I just saw a naked Prince William handcuffed to a lamp post in East Finchley." -- Simon Pegg, who sounds like he's brainstorming ideas for his next comedy