A trackball is a good alternative to a standard computer mouse. The benefit of a trackball is that it does not require major arm movement like a standard mouse. Also, if you have decreased use of you arms and hands, you may still be able to use a trackball.
The type of trackball that is usually most helpful to PALS is one that has a large ball in the center.
If you have good fine motor skills, another option could be a mini trackball:
Trackballs can be purchased at many local stores that carry computer equipment, such as Staples, Office Depot, CompUSA, Best Buy, Circuit City, etc. Here are a few websites that also have this type of trackball:
A trackball that has a small ball off to one side is not recommended for PALS.
More Computer software and hardware products available to PALS: