Left handed mousing

I found this here and was intrigued by the left handed mousing. I know many left handed people in my field, I imagine it is something to do with the problem solving creative waffle that we're supposed to be talented in.

The comment on the picture:
"Actually...
While I am naturally left-handed, I have always used only my right hand to mouse with. But Yahoo's ergonomics class strongly recommended to try switching. (ask me if you want me to convince you why left-handed mousing is better ergonomically). My boss had done it and said it wasn't too hard... so when I got my keyboard tray I decided to try it and it was a pretty easy switch, I like it now. Too bad my personal mouse at home is a right-handed only mouse. So I guess you can call me an "ambi-mouser"."

Caused me to search out this Mr. Freo and thanks to the wonders of the web I found him and picked his brains on this left handed ergonomic thing. He was conginial in his response and I asked could I repost it here with full attribution and he agreed.

Up until now I'd always considered being a left handed computer user a distinct advantage, I could make notes as a browsed around doing research. Everyone else has to stop move the mouse get the pen pad then make the notes etc. I just write as I'm going along. My next concern was I spent rather a lot of money on a pretty nice Microsoft Bluetooth IntelliMouse. I know I know it's not cool to like MS. However I've always said they do some stuff very well. When it comes to hardware that's 360s and Mice. I actually bought this mouse after I began using my Mac Book Pro as my main machine, in the office I just wanted to open it and go. Not have an extra cable trailing around, on top of the Network, Power etc. Anyway it's always easier to clear the decks when needed if peripherals are wireless.

As you can see from the picture, this mouse is VERY much geared for right handed use, I use all the extra buttons for various exposé features. In light of all these questions and thoughts, here are Mr. Freo's thoughts.

While I do write left-handed, I always have moused right-handed (and that is still the most natural thing for me). Even when mousing right-handed, I've never found a significant need to write at the same time as mousing... so that is kind of irrelevant for me.

The basic reason for switching to left-handed is because it'd ergonomically better for you when your keyboard is placed properly. The "middle" of the keyboard, the "g" and the "h" keys should be directly placed centered in front of you (rather than the literal middle of the keyboard"). On the vast majority of keyboards, doing this will put the number pad on the right even further away. Then, if you put the mouse even further to the right from there, it puts a lot of unnecessary strain on you.

Mousing with the left is an alternative which isn't too hard to get used to, it only took me a few days. For me, I have a non-symmetrical mouse for personal use too, so I still mouse right-handed with that. But when I was at work I would mouse left-handed. The result is that it would give my right hand a break for most of the day.

I do like the balancing idea of the g and h being central to body position. I certainly intend to give it a go with my symmetrical wired, again Microsoft, mouse when I move my desk around next.