A program that AutoDesk doesn't support, but has become invaluable in my set of "must-have" tools.
You can easily edit your AutoCAD PGP file (which basically allows you to remap all of your keys. Most people find that many of the commands they most frequently use are just too long to type many times every day.
I, for one, have remapped all my most frequently used commands to my left hand, leaving my right hand free to use the mouse.
The appropriate support files are also included in this ZIP.