A collaboration between the University of Chile and the University of Akron has produced the deformable octahedron robot called OctaWorm. The robot works by having multiple pneumatically driven ball joints that allow it to constrict and expand into a wide variety of shapes, allowing it to traverse very tight spaces like pipes or the rubble of collapsed buildings. The developers see many potential uses beyond search and rescue uses, but also envision tiny versions of the basic design being used inside of the human body. You can read more about OctaWorm over on 3DPrint.com: http://3dprint.com/88873/3d-printed-octaworm-robot/
Below is a photo of the three prototypes of the OctaWorm: