I have no idea if this is allowed but I use a 6-axis "mouse" for 3D modeling, it's USB 2.0 and relatively cheap. I've wanted to build a vex rig and drive an omni-directional bot with this for a while now.
Here's the product:
http://www.3dconnexion.com/3dmouse/spacenavigator.php
X, Y and Z movement (3 axis's)
Z, Y and Z rotation (3 more!)
-Cody
EDIT: Custom drivers can be found of their forums but I'm not sure how the controller station will affect them (I haven't managed to obsess over the new programming this year, soon).