[cfraenkel]

You think you do. The issue is it's just about impossible to isolate translation from rotation. You would always be doing just a little rotating every time you touched the ball, whether you wanted to or not. And any time you tried 'rotating', you'd also be moving the cursor.

6DOF devices have been done (ie https://en.wikipedia.org/wiki/SpaceOrb_360 or https://www.computinghistory.org.uk/det/12416/Logitech-Cyber...). They're sorta fun to use (at first) in CAD for browsing 3D models, but never caught on as once you get good at the CAD UIs, the extra degrees of freedom get in the way more than they help.

[GuinansEyebrows]

rotation works pretty well for scrolling on the kensington slimblade with a little bit of getting-used-to. when it detects rotation, it stops moving the cursor.