Many techniques have been invented for making the mouse pointer more visible. One is a little animation of circles radiating out from it when you press a "locate" button, another is just making it bigger. Yet another is adding "mouse trails" showing the position the pointer was at over the last few frames (though this has the disconcerting effect of making your pointer appear to be a snake). One which I think has been inadequately explored is making it "high density". Normally when you move the mouse the operating system erases the pointer from the old location and plots it at the new location (doing nothing in between) if you move the pointer around quickly in a circle it the pointer seems to appear at discrete locations.
I think it would be better if, in any given frame, the operating system plotted the pointer at the position it was at in the last frame, the position it is at in the current frame and everywhere in between. This would give the impression of a "streak" as you moved the pointer, or a solid circle if you moved it in a rapid circle, as if the pointer is plotted much more often than once per frame - more "densely" in other words. It would be kind of like mouse trails done properly.
Motion Blur for mouse cursors? That sounds awesome.
Adding to that, I wouldn't mind having cleartype for mouse pointers either, in the event I ever need to get subpixel precision when trying to click on things. Doing that would require completely changing house mouse cursors are rendered in Windows though... Which means injecting new code into the operating system.
Unrelated, I once made a version of the Windows Aero mouse cursor that had a built-in drop shadow, since the original cursor already uses an alpha channel and has a lot of unused transparent pixels to its lower right. Saves on processing resources and graphics compatibility headaches due to not having to draw a separate drop shadow. I unfortunately lost that mouse cursor with my last computer, though.
Other enhancements I made were making the inside of the mouse cursor slightly translucent so you could see what was under it better, setting it to run at 60 FPS (which makes the loading wheel look a lot faster and smoother), and making the outline of the cursor change hue... which unfortunately makes for a pretty big file, and consumes extra memory, but who cares, it's awesome.