Haven’t had a chance to try it out yet, but those with the SpaceNavigator and ArcMap 9.2 might want to take a look at the work Jiro Shirota has done.

From the comments:

Demo movie:
http://video.google.com/videoplay?docid=-8574975852358744167

Driver (dll / tlb)
http://www.simplespatial.net/Downloads/ArcMap3DconnexionDriver.zip

You will need .NET 2.0 runtime.