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En español | The only son of Beatle John Lennon and his first wife, Cynthia Powell, Julian Lennon will release a new single — "Someday," featuring Aerosmith's Steven Tyler — on his 50th birthday. A successful musician in the 1980s (the name might have helped), he has recently taken up photography.

The host of MSNBC's hugely popular Morning Joe was once an outspoken Republican congressman from Florida. Never one to avoid controversy, he stepped right in it last fall, criticizing Mitt Romney as being, among other things, "neither a true conservative nor a courageous moderate."

The host of the TBS late-night show Conan, O'Brien will be cracking wise as headliner of the White House Correspondents' Dinner, where press, politicos and celebrities come together, on April 27. O'Brien, of course, made his TV career as host of NBC's Late Night and, briefly, as host of the Tonight Show.

In our hearts, he'll always be the endearingly neurotic Will of television's Will & Grace, but the Toronto-born and -bred actor has moved on. Most recently, he's played a crime-solving schizophrenic neuroscientist in Perception on TNT. According to his Twitter feed, he's now filming season 2, which airs this summer: "Hafta watch!"

The Chinese martial arts champ earned fame in the U.S. with a villainous role in Lethal Weapon 4 in 1998, then in films such as The Expendables and Hero. He had a brush with death in the Maldives during the 2004 tsunami, but, luckily, only ended up with a hurt foot.

Waltrip raced go-carts as a kid and later followed brother Darrell as a race car champ, winning the Daytona 500 twice. Now he owns a team and is an analyst for Fox Sports, and there's talk that his book In the Blink of an Eye is to be made into a movie.

The rather goofy-looking, bespectacled comedic actor is known for his roles in Ghostbusters, Spaceballs and the Honey, I Shrunk the Kids movies. He's been in semiretirement since 1997, though he released a comic country song album called The Agoraphobic Cowboy in 2005.

As if being a nationally known playwright isn't enough — his play Talk Radio was nominated for a Pulitzer — Bogosian has also written and performed six solo off-Broadway shows, written three novels and starred on Law & Order: Criminal Intent. Total slacker.

Now a fixture on best-seller lists, Evanovich started her career writing romance novels but eventually, she jokes on her website, "ran out of sexual positions and decided to write mystery novels." Her 20th book in the Stephanie Plum (a Cheetos-loving bounty hunter) series comes out in November.

A real American idol, the 1960s pop singer ("Take Good Care of My Baby," "Run to Him") was recruited at 15 to fill in after Buddy Holly's plane crash. He performed for decades more, but was diagnosed with Alzheimer's disease in 2011, and announced his retirement last year.

From 1967 to 1978, the beloved comedian broke ground for all future funny women with her iconic sketch comedy television series. These days she performs a one-woman show called Laughter and Reflection With Carol Burnett a few times a year. She recently told AARP, "It keeps the old gray matter ticking."

The outlaw-country singer and activist — his long hair all grown back — is currently on what he calls "The Old Farts and Jackass" tour, winding up in August at the Hollywood Bowl. He's releasing a new album this month called Let's Face the Music and Dance, with covers of classic tunes.

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