some modern mice can scroll horizontally as well as vertically, using a tilting scroll-wheel (introduced by microsoft), scroll ball (found, for example, on apple's mighty mouse), pointing stick, touchpad (as on apple's magic mouse), optical sensor, or a second scroll wheel. logitech mice with 'free spinning' scroll wheels use a 14 gram scroll wheel with high rotational inertia like a flywheel that can be used to quickly scroll through long pages and lists. a peculiar early example was a mouse by saitek which had a joystick-style hatswitch on it.