I use the Logitech Marble Mouse and, in addition to taking breaks, I switch hands every couple of days. After I got used to using the track ball with my right hand (I'm right-handed), it was fairly easy to get used to using it with my left hand (I'm not ambidextrous by any stretch of the imagination).
Switching hands also had the added side effect of confusing my co-workers ("I thought you were right-handed?")
I use the Logitech Marble Mouse and, in addition to taking breaks, I switch hands every couple of days. After I got used to using the track ball with my right hand (I'm right-handed), it was fairly easy to get used to using it with my left hand (I'm not ambidextrous by any stretch of the imagination). Switching hands also had the added side effect of confusing my co-workers ("I thought you were right-handed?")