Scroll Reverser is described as 'free app for Mac OS X Snow Leopard and Leopard that reverses the direction of scrolling. With reverse scrolling, the page content moves in the same direction that you move your fingers, just like on iOS devices and OS X Lion' and is an app. There are four alternatives to Scroll Reverser for Mac and Windows. The best alternative is MOS, which is both free and Open Source. Other great apps like Scroll Reverser are Mac Mouse Fix, Smart Scroll and ScrollNavigator.
Switch between Spaces, use Windows-style Back and Forward, and more - right from your mouse. Also features a refined Smooth-Scrolling algorithm that strikes a perfect balance between fluidity and control.
ScrollNavigator helps you to scroll your documents horizontally and vertically. Simply click and hold down the right (or the middle) mouse button anywhere in a window and move the mouse to scroll the window contents.