If you don't have a Mighty Mouse, and just a run of the mill 3rd party mouse with one scroll wheel to scroll up/down, don't despair! With this trick.. you can scroll horizontally in most OS X apps. Here is how to do it: Simply hold down the SHIFT key and scroll forward to move to the right, or scroll backwards to move to the left. Now, if you don't have horizontal scrollbars at the bottom of the window.. this isn't going to work. Resize the window until you see the horizontal bar at the bottom. Here is a bonus tip: If you have update to 10.4.8, there is a new feature - Zoom with the scroll wheel. Here is how to do it: Hold down CONTROL and move the scroll wheel forward or backward. The screen will ZOOM IN and OUT. No mouse? If your portable Mac supports scrolling with the trackpad (all newer Macs do), simply hold down CONTROL and then scroll with your two fingers touching the pad.