Can I reverse the scroll direction of my mouse? I upgraded to OS X Mountain Lion from Snow Leopard and all of a sudden my scrolls in the browser window (chrome, Firefox etc) have reversed. 

I need to scroll up to go down and vice-versa. Is there a way to change the direction ?
The system preference for scroll direction is all-or-nothing and applies to every input device uniformly.  With some things, this just doesn't make sense.  If you want fine-grained control of which input devices scroll in which way (for example, if you want touchpads to use the "natural" scrolling while having the scroll wheel use traditional scrolling), try ScrollReverser.