My former jobs have often required me to move around between various laptops and a host of PC desktops & Sun workstations (which usually use the proprietary Sun keyboard). I often was working at different computers each day. Add to this the times I often help family or friends with their computers, or do projects/training/presentations/whatever on other people's computers, and I just haven't had the option of choosing one particular keyboard & solely using it.<br>When touch typing, the work is split more or less evenly between my hands, so neither side takes the lions' share of the load. But much of computer work is not touch typing. Small, single button strokes or short strings add up to much of the bulk of my typing, and typically just gets done with my dominant hand, along with every time I hit the Enter button. This loads the work more onto that side, while my off hand just rests. Add mousing with my dominant hand to that situation, and the work load is definitely unbalanced.<br>Twice during my career with computers, I have developed pain, starting minor and growing to severe, shooting up my dominant arm. Each time, I realized, I could even out the uneven load on my dominant hand if I merely switched my mousing to my non-dominant hand. Each time, the pain receded and slowly disappeared.<br>I only had to learn the lesson twice for it to stick: I have, since then, always moused with my off hand. As I move around among and between different types of computers with different types of keyboards, I can still get the benefit of splitting the work load more or less evenly between hands just by moving the mouse/ball/whatever & pad from one side to the other, or just making myself use my left fingers on the trackball/touchpad/whatever. It sets me free to use whatever keyboard is available, and still feel confident I am staying healthy.<br>I often tell people this, but I know of no other person who has adopted this practice. I guess they don't feel the pain I did. I'm fairly certain I wouldn't be doing it otherwise, myself. In only one case do I know that the person still has ongoing problems with pain & still does all the extra work with his same hand anyway. I guess it's just too weird to him to consider mousing left-handed.