I received the Space Navigator controller yesterday, and finally had time to experiment with it tonight after work. The device is very solid, actually on the magnitude of a paperweight (literally). On first pass I used the 3rd party driver listed in the blog post below that simulates a joystick. I configured SL as detailed in the instructions and got mixed results. I then stumbled on a Wiki post at the official Second Life Wiki:
This article had instructions for using the most current 3D-Connexxion drivers with SL. This worked a lot smoother than the 3rd party RBC9 driver. I was a bit shocked to find out that the use of this controller is limited to only controlling the Flycam (free floating camera position, and a “not finished” feature of SL), and not your avatar in SL.
There’s got to be a way to map keys to the axis of this controller, just gotta be. I only had a few hours with this tonight, so I will keep searching and post more information later. For now, hang back and only buy this if you are really hard core into making machinima, or just like putting together flybys with Fraps (I fall into the later).