Trained as a marine biologist, today Cristina Mittermeier is a photographer, author and scholar who uses her camera to help pursue her goal of a better, greener planet.

She’s the Executive Director of the International League of Conservation Photographers, a group which uses the camera lens to educate, entertain and enlighten people all over the world.

So it should be no surprise that her time with the indigenous Kayapo tribe of Brazil has delivered a wealth of incredible images.

Photographer Rick Sammon journeys all over the world to get great shots.

And now he’s sharing those shots–and his photography expertise–with us.

Check out his newest slideshow, which offers astoundingly intimate photos of polar bears, as well as some insight on what makes a great photo.

America’s northern neighbor Canada has its share of national icons, even if they sometimes seem to be overshadowed by more famous American monuments.

From Toronto’s CN Tower to historic Quebec to the slopes of Banff, Canada’s hottest vacation spots are scattered all across the world’s second-biggest country (in terms of area).

So view and learn about some of Canada’s lesser-known treasures in this slideshow.

When asked about his specialty, photographer Rick Sammon responds, “My specialty is not specializing.”

Sammon has photographed in almost 100 countries around the world.

Today, he shares his favorite pictures of Antarctica from a journey with Quark Expeditions, along with handy tips on how you, too, can capture that perfect shot.

Peter was a co-chair at the recent 2008 Airline Ambassadors UN Global Compassion Ball.

The event featured guests including Meredith Vieira and Hoda Kotb from Today, as well as UN Secretary-General Ban Ki-moon, Dr. Patch Adams, and even Miss America.

Check out these photos from the event, held in New York City on October 16, 2008.

Alison Wright is a globe-trotting photojournalist whose work encompasses a large number of the world’s varied cultures.

Her latest book, Learning to Breathe, recounts her experiences after a near-fatal bus crash in Laos and how that changed her life.

PeterGreenberg.com is proud to present a collection of her photographs focused on her travels in Asia, from India to Tibet to Japan and beyond.