In this laboratory, we are using Apple iMacs for our workstations, which are each equipped with a Mighty Mouse. This mouse has four buttons (even though it looks like it has only one). By default, it is set-up in a manner that is suboptimal for our purposes. I suggest you reconfigure it as shown.
Figure 1, “Configuring the Mighty Mouse” shows my suggested configuration. I’ve enabled the “middle” mouse button (Button 3) as well as the “right” (Secondary) mouse button. Note that I’ve also disabled the squeeze button, as this confuses some users at first; ergonimically it’s a little worrying.
Just in case you’re wondering about the usefulness or otherwise of something that is in essence a one-button mouse, consider this: on a standard multi-button mouse, you use one finger to do most of the clicking and dragging. This causes a lot of tension in your hands, which can lead to disorders such as RSI/OOS. By having a one-button case, the user can use the weight of their entire hand to effect the majority of clicks and drags, causing less stress. The only bit that really requires a single finger is a secondary click (right-click for most people). That said, I do have some issues with the design of the Mighty Mouse, but it’s better than a standard mouse from an ergonomic point-of-view.