In Apple’s award-winning ad entitled “The Underdogs," we see how four colleagues put together a presentation and prototype in just two days using the company's products and technology.

Japanese dancer Nagisa Hattori and R&B star Al B Sure appeal to everyone to support the countless victims of the earthquake in Japan and give donations to the American Red Cross, Global Giving, Save the Children, and other organizations. Copyright: PopTopicTV

In the coastal town of Laguna, Brazil, a strong bond has formed between wild dolphins and local fishermen over generations. The dolphins herd schools of fish towards the shoreline and then give distinct signals telling the fishermen when to cast their nets.

At a privately-owned wildlife park in South Africa, Or Lazmi has integrated herself into a group of four lions. Having known her since they were cubs, the lions treat her as a dominant figure and allow her to get extremely close.

An American abroad: Joe Evans takes us on a tour of his apartment in Chiba, Japan. Look through his eyes as he encounters cultural differences in the mundane objects of daily life.

American finance student Jack Thomas tells about his life in London.

Enjoy this mix of Amy Winehouse songs, which shows her musical ability and the diversity of her sound.

Have you ever wondered what the rules of American Football are? Here's a quick guide.

Rachel's English: For some people, "s" and "sh" sound the same. As Rachel explains, the positions for these two sounds are quite different. Learn the difference in tongue and lip position, and practice with minimal pairs.

There are few places on Earth as breathtakingly spectacular as the Grand Canyon. One of the last great American wildernesses to be charted and explored, this mile deep rift in the landscape has been designated a national park. Among the wildlife to dwell in this remote and often harsh environment are the sure-footed, hard-headed, and sometimes quarrelsome bighorn sheep.

When battle is done, the exhausted bighorns make their way to the canyon rim. But they must be wary, as the canyon is also home to large predators, and a fierce mountain lion is on the prowl. The awe-inspiring vastness of the Grand Canyon attracts numerous tourists, but many will go no further than the lookout points due to the challenging terrain.

The woodpeckers have cleverly used a pine tree to hide the acorns they collect, and are very good at working together. They must simultaneously keep a lookout for predators and guard their wealth from other animals keen to pilfer an easy meal!

One of the rarest birds in the world, and the largest in the Americas, the California condor soars majestically over the canyon. A growing herd of bison roams the north rim, but their presence in the park is ruffling some feathers!

The prairie dogs are on constant alert, but the kit fox has a young family to feed, and prairie dogs are certainly on its menu! As the heat rises and birds circle the sky, the creatures below need to assess which may be a threat, but sometimes, not all is as it seems...

For centuries, the Grand Canyon and its river were thought to be impassable, but in the nineteenth century, steep paths were carved into its walls. However, for the agile bighorn sheep and summer visitors like the violet-green swallow, this is still nature’s playground.