we have a beta version of the addin for Maya 8 and 8.5. If you are interested please send me a private message with your details (linux version, architecture, email address, Maya version)
For Google Earth there is no support available at the moment. See here.
Concerning the support for Blender see this post. You can find more links in that post.
I believe there may be some user created solutions out there, which we can't recommend but you might look around the 'Net. We plan to take a look at Blender, but at this time, I can't provide a reasonable answer. Be assured that we know there is request for this support, and we take that seriously.
the SpaceNavigator was designed as an additional device used with the left hand (if you are right handed) to navigate in 3D. For example with Maya, ProE or Google Earth (hopefully with 3D navigation device support under Linux soon).
There is no support to move the cursor with the SpaceNavigator.