James Cracknell is a championship rower that has won two Olympic gold medals and climbed to the top of his sport.

Today, Cracknell is out with a 'trilogy' of programs that shows him performing and taking part in some of the world's toughest challenges.

In the first programme called "The Toughest Race on Earth", Cracknell runs the infamous marathon des Sables which is a six-day, 151 mile endurance race across the Sahara Desert.

The second programme starts with an attempt to cross the U.S. using only four sporting disciplines - cycling, running, rowing and swimming. He had to make his way from Los Angeles to New York in just 18 days. Unfortunately, just five days into the journey, Cracknell was struck with a near-fatal head injury.

Even though he almost lost his life, he continued on with the third programme which saw him take on the Yukon Arctic Ultra - cycling 430 miles across the frozen wilderness.

Here's your chance to have your questions answered by this courageous man.

Please leave your questions below and be sure to include where you're writing from.

With the white sandy beaches of Acapulco to the night life of Cancun just some of the places attracting so many tourists to Mexico, is the threat of violence putting them off?

Every year millions of tourists come to Mexico, with many coming for the beautiful weather and cheap prices. This brought in almost $12 billion last year, which shows just how important tourism and the jobs it creates are to the economy.

However, drug-related violence in Mexico continues to plague the country, with more than thirty five thousand people killed since 2006. President Calderon deployed more than 40,000 troops and federal police to the worst-affected states to try and put an end to this problem.

Tune in tonight as CNN’s Rafael Romo looks at how the drug violence has affected Acapulco, once the destination of choice for people on spring break.

We want to hear from you on this subject. Are you going to Acapulco? Are you worried about your safety? What can the government do to attract tourists to this once idyllic coastal town?

Share your stories with us and be sure to say where you’re writing from.

Actress and singer Emmy Rossum has already impressed audiences for captivating performances in films such as "The Phantom of the Opera" and "The Day After Tomorrow" - all at the young age of only twenty-three.

Rossum is currently the star of the new Showtime series called "Shameless" alongside well-known acting veteran William H Macy.

Before that, she had her big break in a leading role in the film-based musical "The Phantom of the Opera" where she earned a Golden Globe nomination for her role.

Rossum is also an accomplished singer, recording her first album in 2007 for Geffen records called "Inside Out".

Here's your chance to quiz Emmy Rossum so please leave your questions below and be sure to include where you're writing from.

She is an award- winning actress with more than forty-five films to her name.

But these days she spends most of her time far from Hollywood, instead traveling to conflict and disaster zones.

She was named by "Time Magazine" in 2008 as one of the most influential people in the world – clout that Mia Farrow hopes will help bring peace to Darfur.

Indeed, the actress – who was once married to Frank Sinatra – has long been a leading lady.

She's starred in films including "Rosemary's Baby" and "The Great Gatsby", though she is best known for the 13 movies she made with her former muse Woody Allen.

But since 2000, Mia has dedicated herself to her role as a UNICEF Ambassador, traveling to trouble spots that include Sudan, the Democratic Republic of Congo, Chad and Haiti.

Her focus is to raise money and awareness for the women and children affected by the violence.

She has just returned from her latest trip to Sudan's conflict-ravaged south.

Here's your chance to have your questions answered by Mia Farrow.

Please leave your questions below and be sure to include where you're writing from.

For over a decade we knew him as bar owner Sam Malone in the hit TV series "Cheers".

Thirty years on, he's still gracing our small screens and is now known as the womanizing party-goer George in the HBO series "Bored To Death".

As a multiple Emmy and Golden Globe winning actor, Ted Danson has long been making us laugh and cry, but he's also been urging us to save our oceans.

Danson was propelled into becoming an environmentalist in the 1980’s after coming across a “water polluted, no swimming” sign with his children on a Santa Monica beach.

He decided to try and turn the tide and co-founded what has now become the world’s largest international ocean conservation and advocacy organization, Oceana.

The 63- year- old has now documented the threats to our oceans in a new book “Oceana: Our Endangered Oceans and What We Can Do To Save Them”.

He's your chance to have your questions answered by actor and activist Ted Danson.

Please leave your questions below and be sure to include where you're writing from.