Disney Research, together with Carnegie Mellon University, has developed a system that lets animated images from two separate handheld projectors interact with each other on the same surface.
The SideBySide device is, of course, a natural for games, but can also be used to exchange contact information, or even share data files.
"Smartphones have made it possible for us to communicate, play games and retrieve information from the Web wherever we might be, but our interaction with the devices remains a largely solitary, single user experience," says Karl Willis, a lab associate at Disney Research.
"Now that handheld projectors have become a reality, we finally have a technology that allows us to create a new way for people to interact in the real world."
The handheld projectors emit both visible and infrared light and contain a camera for monitoring the projected images, a ranging sensor and an inertial measurement unit.
The infrared channel is used to project markers that help the system recognize when images are moving or overlapping and communicate information between the devices.
The researchers have developed a number of applications to demonstrate the capabilities of the technology. Games include Boxing, in which matches are performed without a ring; Cannon, in which players knock a stack of bricks off a platform by firing a cannon ball from one screen to another; and Gorilla, in which one player uses a plane and a net to catch the other player's gorilla.
They've also developed a 3D viewer, which allows two users to control and explore a 3D model together, and applications for exchanging contact information and transferring files.
There's a video of the system in action, here.