Mouse pointer on my MacBook moves by itself

I stumbled upon a thread in Apple Snow Leopard discussion forum. a bit old thread, but the problem is same. And it seems a lot of people have been facing the same problem. more than 120+ comments and yet no one found a good solution. They have tried various solutions like replacing the mouse with wired one, updating the browser(!) and someone even related it to more than one monitor being connected. But only those who ended up replacing the trackpad, seemed to have gotten rid of it. and it also makes sense I think. If no mouse is connected, bluetooth is turned off, and yet the pointer is moving, then it has to be some problem with the trackpad. You're welcome to wait for any further solutions, replacing the trackpad can be the last resort.

If you have a touch screen, turn it off. I noticed the ripple effect of the cursor that should only happen when you touch the screen, not when using the touch pad or mouse. Fixed the problem right away. After a week I turned the touch screen back on, calibrated it and it was fine again. Appears you need to do that about every eight weeks.