The CCNY Robotics Lab was the first to bring us Kinect drivers for ROS, so it's not surprising that they have some awesome Kinect demos they have been working on.
In the above video, they show some of the latest results of their 6D pose estimation. Simply by moving the Kinect around an office, they are able to register multiple scans together and create a 3D model of the scene. Their code works with no extra sensors: they simply move around the Kinect freehand.
The work was done by Ivan Dryanovski, Bill Morris, Ravi Kaushik, and Dr. Jizhong Xiao. They are using custom RGB-D feature descriptors for the scan registration and use OpenCV, PCL, and ROS under the hood. They are working on releasing and documenting their code. In the meantime, you can checkout the rest of the cool software available in ccny-ros-pkg.