That's exactly what i'm looking to do.. I've been investigating for a week or so and it looks like the spacenavigator is the best solution. Mine arrived today so I'm just playing around with it at the moment
Take a look here;
http://www.mp3car.com/vbulletin/soft...nt-thread.html
and here
http://www.3dconnexion.com/forum/viewtopic.php?t=336
HTH