I shure like the 3Dconnexion 3D mouse that most of us are using.
But there is a thing that lets you even more directly interact with your 3D model:
https://leapmotion.com/
Imagine to edit a feature or sketch directly with your fingers. Image to pull and push the geometry just as in freestyle - but even more directly....
Like that, users can input their ideas to the software just more directly.
This would also be ideal for presenting in meetings and navigation in digital mockups I would say! Even less CAD agnostic people like the boss can then turn a 3D model without making it look awkward.
That is impressive! PTC, please impress us, too 