Recent Emacs versions have a wonderful capacity to hide the mouse pointer as soon as you type and insert characters in a buffer. This is controlled by the `make-pointer-invisible' variable, which is set to t by default.
However that does not hide the pointer when simply moving the cursor on screen. Therefore, I've started to use `mouse-avoidance-mode', which make the mouse pointer jump if your cursor hits it.
Unfortunately, if your cursor hits the invisible mouse pointer, `mouse-avoidance-mode' makes it jump too, because it does not know it is invisible.
Well, it did not know. Now it does, thanks to my patches which have been merged in Emacs 24. Using the new function frame-pointer-invisible-p, one can know if the mouse pointer has been hidden by Emacs. Therefore I enhanced `mouse-avoidance-mode' to use it, and everything is alright now. :-)