There are other 3D mouse/trackball solutions on the market already, like 3Dconnexion’s SpacePilot Pro, but I like what axsotic has done with their 3D-Spheric-Mouse. At first glance it doesn’t appear to do anything different than your standard trackball, which would also let you rotate a 3D model in any direction, however the sphere can also be pushed, pulled and even lifted to re-position a model in 3D space.