Here are a couple of simple but potentially time saving (or maybe just index-finger-saving) tips. First, If you use the scroll arrows at the ends of the scroll bars to page through long documents, you may be surprised to find you can save yourself a mouse click and a delay each time you want to reverse your scroll direction. How? Well, it turns out that the scroll bar arrows in OS X are sensitive to “mouse over” actions if another scroll arrow has already been activated.
Putting that in another (hopefully clearer) way, if you click-and-hold on one scroll arrow, you can move your mouse off of it and onto the opposite-direction arrow, and scrolling will immediately reverse. In previous versions of the Mac OS, you would have to first release the mouse button, move to the opposite arrow, then click-and-hold on that arrow and wait for scrolling to commence again. This not only took an extra mouse click, but you had to wait for the scrolling to begin again.
Perhaps a demonstration will help; this 740KB archive contains two short video clips. The first, old_scroll.mov , shows the old behavior. After starting to scroll down, I lifted my finger from the mouse button, moved to the Page Up arrow, then pressed and held the mouse button down again. In new_scroll.mov , I used the new “don’t release” method—I just moved the mouse from one arrow to the other. Although you can’t see that my finger stayed down the whole time, you can see that there’s no wasted time when reversing scroll directions—it happens instantly.
To make this trick useful at all, you’ll need to have your scroll bars together—there’s not much point to holding the mouse button down while you move the mouse 10 inches down your screen from the Page Up arrow to the Page Down arrow. The easy way to do this is to visit the Appearance System Preferences panel, and click the Together radio button next to “Place scroll arrows.” However, this gives you a double-scroll arrow only at the bottom of the scroll bar area. That’s not a lot of help if your mouse is at the top of the scroll bar. With just a tiny bit of Terminal work, though, you can have the best of both worlds—double scroll arrows at both the top and the bottom of the scroll bar.
Launch Terminal (in /Applications: Utilities) and type in the following command, then press Return:
defaults write "Apple Global Domain" AppleScrollBarVariant DoubleBoth
You’ll now have double arrows at both ends of the scroll bar in any newly-launched applications. Any applications that were open when the command was executed, however, will have to be relaunched for the changes to take effect. If you ever tire of this, the easiest way to revert to another style of scroll bar arrows is to just pick one of the other two styles in the Appearance System Preferences panel.
Note: If an application has a really small window that's designed to have scroll bars, and you have double scroll arrows at both ends, it's possible you won't see the scroll bar at all (as there's no room to show it). If this happens to you, try the arrow keys to see if they'll scroll the list. If not, you'll have to disable this handy feature in order to scroll that dialog box.
By using both these tricks together, you can save quite a bit of time, mouse clicking, and scrolling. And yes, you could also avoid all of this by simply purchasing a scroll-wheel-equipped mouse (which I highly recommend, BTW). However, there may be times you find yourself without a scrolling mouse…so remember this hint at those times, and you’ll save yourself some aggravation.