James Cameron will ride this submersible to the deepest point in the ocean

Meet the Deepsea Challenger, a one-man submersible craft capable of withstanding pressures at the deepest point in the ocean—Challenger Deep in the Pacific's Mariana Trench. Sometime in the next few weeks, this sub will carry filmmaker James Cameron into the Challenger Deep. He'll become the third human to visit that place, and the first since a two-man Navy sub made the dive in 1960.

As you see it in this photo, Deepsea Challenger is actually sideways. The sub will fall into and rise out of Challenger Deep in a vertical configuration, with Cameron at the bottom in a spherical steel pod. You can't see the spherical part in this image, but the pod is attached. It's in the end of the craft that's still slightly out of the water—the left-hand side of the photo.

Cameron's descent will be very different from the 1960 expedition, which wasn't able to see much because their craft stirred up so much debris in the bottom of the trench. Deepsea Challenger is designed to avoid this problem and Cameron will also spend a much longer amount of time at the bottom—several hours instead of just 20 minutes. He'll also film 3D footage of the trench, and collect animal and rock specimens.

You can see more pictures of the Deepsea Challenger at National Geographic News.

That site also has a longer story explaining, in more depth (harhar), how the sub will work and how Cameron's expedition contributes to science.

Finally, I'd like to take a minute to apologize to everyone who saw Titanic multiple times in the theater. If I'd known back then that your devotion to Leonardo DiCaprio would one day help fund cool stuff like this, I wouldn't have rolled my eyes at you nearly as often.