Sandio has a mouse that handles 2D and 3D. Think of combining the shape of a regular mouse with the functions of a 3dconnexion "space" mouse.
The Sandio works by having sliding buttons on the top and sides. Depending on how you move the buttons, you can tilt, twist, and zoom in 3D. The video at sandiotech.com shows how it works (click on English). Just $80.
Tip o' the hat to Don Beaton.