In the mid-90s at work, I was known as that guy who used a left-handed mouse at all times (I am right-handed.)
I would swap L/R button functions on the Sun4 3-button optical mouse and set it to the left of the keyboard. This is a comfortable and natural position, especially considering the placement of the numpad.
Very soon, the word was out in the office, and NOBODY attempted to borrow my workstation!