Brooke Burke tweets a photo of herself on Dec. 5, 2012, prior to an operation to remove her thyroid after she was diagnosed with thyroid cancer. "Last looks at my neck," she wrote on Twitter. After the surgery, the "Dancing with the Stars" co-host tweeted, "made it through my surgery, Thank God! so far so good F*** Cancer!"

Ireland Baldwin, the 16-year-old daughter of Alec Baldwin and Kim Basinger, tweeted this image of herself Mud-Boarding on Twitter, Sept. 1, 2012, saying, "#gliding". (<a href="https://twitter.com/IrelandBBaldwin" target="external">Click here to see Ireland Baldwin's Twitter account.</a>)

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Tom Hanks son Chester Hanks, an aspiring rapper who goes by the name Chet Haze, posted shirtless photos on his Twitter page using Instagram with the words, "Ladies... This is for you." Apparently, it worked. After gaining 300 followers overnight, he wrote, "Lol, I should have took my shirt off a long time ago."

Tom Cruise as Stacee Jaxx tweets photo from"'Rock of Ages" set. Cruise is seen shirtless as he's rocking it out.

Even while tweeting from abroad Dec. 18, Lady Gaga says she's is proud to be an American. Via twitter, the pop star celebrated the U.S. Senate vote to let gays serve openly in the military by posting a picture of herself holding a white card reading "Full Equality." The star, who has used her fame to campaign, wrote multiple tweets, including "Can't hold back the tears+pride. We did it!"

Kirstie Alley dropped major pounds, and she shared the news via Twitter. "I've lost over 50 lbs...and I'm having the time of my of my life...30 more to goooooooooooooooooooooooooooooooooo," she wrote. Earlier this year, Alley admitted she weighed 230 pounds.

Demi Moore posted a candid photo of herself on Twitter, wearing nothing but a bikini and smile. The 47-year-old wrote, "Maybe this is more like summer!"

Rihanna posted a close-up photo of her face on her Twitter page after burning her forehead with a curling iron. She wrote, "New hair...new curling iron burn...damn 5head always in the way." "5-head" is the singer's humurous nickname for her forehead.

Former "Tonight Show" host Conan O'Brien joined the Twittersphere last week and quickly amassed nearly 470,000 followers. But now several other Coco-related Twitter accounts have popped up online. His beard, freckles, monkey and Sharpie each have a separate Twitter feed. After O'Brien's Twitter account posted, "Today I connected all the freckles on my arm with a Sharpie. It spells out RIKSHAZ9LIRK. Clearly I am The Chosen One," his Sharpie wrote back, "These past weeks of connecting freckles and writing Leno-inspired bathroom graffiti are enough already. Let's get back to work."

Jim Carrey welcomed his grandson, Jackson Riley Santana, with a tweet Saturday. His daughter, Jane Carrey, 22, gave birth Friday in Los Angeles. On his Twitter page, the 47-year-old actor posted his grandson's picture and wrote: "This is what 7lbs 11 oz. of Calfornia [sic] dynomite [sic] looks like!"

"It's amaziing how good it feels when someone knows how to love your body! I am having withdrawals from a certain guy lol :) So turns out i prefer chocolate over vanilla. interesting," Amanda Bynes wrote on her Twitter page. She is rumored to be with rapper Kid Cudi.