So it's not happening quite as quickly as we'd been told in previous stories on the subject, but the 3D revolution does seem to be coming. One of the hold-ups has been convincing theater owners to upgrade to projection and display systems that can handle this new wave of 3D tech—it takes around $75,000 to switch over an old theater. But the 3D companies have been arguing that this upgrade enables theaters to become more than just movie houses: They can show concerts, sporting events, even operas in 3D, and charge more per seat.

Apparently James Cameron's Titanic obsession is genetic. His brother Mike's engineering firm, Dark Matter, custom-built two remotely operated vehicles to probe the Titanic's multitude of staterooms, stairwells and cargo spaces. Brother James then used these ROVs to help shoot the 3-D Imax documentary, Ghosts of the Abyss, which opens April 11. We spoke with the brothers about the ROVs, the Titanic and why the Navy is interested in doing business with them.

Popular Science There are plenty of ROVs out there. Why build your own?