If you haven't looked at them before take a look at 3D mice. Commonly used in 3D modeling and CAD drafting they are the best at interacting with items in 3D space but I wouldn't actually like one for text/flat image interaction. Mapping 3D movements to a flat plane is less intuitive than it may seem if you haven't done it. Most the 3D professionals I know use a touchpad or regular mouse for 99% of the non-3D usage.