I use these as well. One of the biggest benefits of the track ball is that the cursor movements can be issolated from button clicks. This lets you put the cursor at the exact location you are after, then without touching the ball, you can do your clicks.
This can sometimes be difficult to do using a mouse because the mouse moves just a little when you click. The ball also lets you "throw" the cursor where you want it it to go. If you decide to try one of these, I suggest you start out by being very conscience of your hand/arm position. You want to develop good habits that will prevent carple (sp?) tunnel. I have three of these track balls. One for each machine I code on. I did manage to wear out one of the buttons on the machine I use at work (8 hrs/day for 3 years). I was able to swap the switch that was bad with one that I never used and I am still using now. I love my track balls! Ben
