Mouse cursor skipping when moving My mouse cursor seems to be skipping around. Could this be a virus?

USB Mouse, Macbook Intel Core Duo 2
It is unlikely this is due to a virus, as there are far more obvious explanations.

Whatever type of mouse, you should first attempt to clean it when movements skip. Dirt might be interfering the laser or other sensors. You can use a slightly damp cloth for cleaning it. A mild detergent could help for greasy dirt accumulations.

If you are using a laser mouse, it might have difficulties tracking movement due to the type of surface you are using it on. This is especially common on glass or other homogeneous surfaces with very little texture. Using a mousepad should improve your experience in those cases.

If all else fails, maybe your mouse is up for replacement.