I have a two mouses: one for each hand. How can I set the primary mouse button separately for each mouse? I would like the mouse I am using for my left hand to use the right button as the primary button.  However, it appears that this setting is global so that it impacts the setting for my right handed mouse as well.  Is there a way to set this up so that I don't need to order special left-handed hardware?
Use ControllerMate

You can reprogram virtually any button (keyboard, MIDI key, mouse key, etc.) to carry out any number of pre-defined actions.


  Reconfigure drivers
  
  Driver configurations can be used to change the default behavior of a
  keyboard or mouse that uses ControllerMate's driver.
  
  All buttons on a keyboard have some default function or another. Most
  are useful, some are not. A driver configuration allows one button on
  a keyboard act like another, or can turn a button off completely.
  Buttons that have been turned off can still be used to trigger
  building blocks.
  
  A driver configuration for a mouse can include a custom acceleration
  curve. This curve can be one of the standard curves, a standard curve
  with an adjusted speed or sensitivity, or an entirely custom curve
  created point by point.
  
  Multiple configurations can be created for the same keyboard or mouse
  — use building blocks to control when a configuration is active.