(Apologies if this text gets choppy; Newsgrazer on the Next I'm using is not
too bright about wrapping.)
There are a few 3-button mice on the market that are purported to work with MacX. I just got a Logitech MouseMan and would like to offer my comments and solicit suggestions.
The mouse is a 3-button mouse with a standard ADB plug. The plug has a 'pass through' connection so that other ADB devices, e.g. the old mouse, can be attached to it. In fact,
my old mouse is attached through it and still works fine.