Support for 3D mouses and other N-degrees of Freedom devices was added to Blender.
Each device must be enabled via a plug-in. So far, only 3D-connexion have a plug-in which you can download from their site : www.3dconnexion.com/solutions/blender.php
Plug-ins must be installed in the plugins folder of blender.3D mouses and devices alike can be used for :
navigating the view in turntable mode,
navigating the view in fly mode
transform the selected object.
When a device is found, 2 new icons appears in the 3D view header. The first let you choose the ndof mode, the second toggle the dominant axis sub-mode, where only one axis or rotation is done at a time.
The modes choices are also mapped on the device buttons.
Support is preliminary, and other modes are likely to be added.