This is the perfect place to keep your cat, your coffee cup, or in [Jacek]’s case, your fantastic DIY trackball ... to the computer. To send the click events, [Jacek] baked some mouse buttons ...

But we here at Hackaday don’t judge based on alternate input lifestyles, and we quite like this billiard ball trackball mouse. A trackball aficionado, [Adam Haile] spotted a billiard ball ...