The SpaceNavigator is now working in Orbiter with the latest beta drivers  at http://www.3dconnexion.com, so I thought I'd share my configs to save others the hassle of setting it up themselves. The drivers are still buggy so I've had to map the roll axis to the keyboard but it's still very workable. The zip contains both the driver config and an ini file for Fly-By-Wire. Both need to be installed manually. (Don't forget to back up your existing FBW config if you think you might be needing it again.)
Update: fixed the direction of the x-axis translation.
Update2: tweaked the roll settings to reduce the twitchiness.