This is a robot that can catch a ball thrown at it. It is a delta robot with a grabber on the end effector. This design allows the robot to move the grabber with the speed and precision necessary to catch a ball flying through the air.
It uses two NXTcam cameras to allow it to estimate the trajectory of the ball in 3D. For more information about how this works, see this post.
For more information and pictures, or for any questions or comments, see the project homepage.