Mac OS X Scrolling Tips
Do we take anything more for granted than scrolling in a window that's too small to show its entire contents? Well, breathing probably outranks scrolling, but most of us don't spend much time thinking about how we scroll. Read these tips to learn how to go beyond the basics of the scroll bar and obvious navigation keys like the arrows, Home and End, and Page Up and Page Down. And all this comes without spending a dime on a scroll wheel-enabled mouse, helpful though such a critter might be.
Double Arrow Scroll Bars
Apple's default settings for scroll bars have never made sense. The settings are happy to let you put single arrows on either end of the scroll bar (an up arrow at the top and a down arrow at the bottom), or to place double arrows on one end of the scroll bar (both up and down arrows at the bottom of the scroll bar). But Apple doesn't reveal the obvious third choice of double arrows at both ends of the scroll bar, even though the necessary code has long been built into the classic Mac OS and Mac OS X.
In Mac OS 8.5 through Mac OS 9 (and for Classic applications in Mac OS X), Tom Schmidt's freeware Scroll Bars (5.6K download) lets you enable double arrows at each end of scroll bars. In Mac OS X, you can use Marcel Bresink's free TinkerTool 2 (480K download) to enable double arrows at each end of scroll bars (along with many other cool features).
If you're not bothered by the command line, a quick Unix command will give you double scroll arrows even faster than downloading and using TinkerTool. Just run the Terminal and paste the following line in at the prompt (I assume you need an administrator-level account to do this). Then log out and log back in or restart your Mac to start using the double arrows.
defaults write "Apple Global Domain" AppleScrollBarVariant DoubleBoth
If you decide you don't like the double scroll arrows, you can switch back to one of Apple's defaults using the Appearance control panel's Options tab in Mac OS 9 (most easily accessible from the Apple menu when you're in a Classic application in Mac OS X) or via Mac OS X's General preferences pane.
In particularly long documents, scrolling can become tedious, which may account for why Apple added a new option for what happens when you click in an empty part of the scroll bar. Traditionally, the document scrolls to the next page, which is easily understandable and gives you a large target when choosing where in the scroll bar to click. In Mac OS X's General preferences pane you can now also choose a mode in which clicking in the scroll bar scrolls the document not a page, but to the location in the document that corresponds with your click. So, if you're at the top of your document and you click halfway down, your document scrolls to roughly the halfway point. Click again at the bottom of the scroll bar and you scroll all the way down instantly. This mode works for Cocoa and Carbon applications, but not for Classic applications.
Honestly, I have this option turned on for one of my Macs, and it drives me batty, since I must constantly evaluate how long my document is and try to imagine what location in the scroll bar corresponds with the desired spot in the window. Luckily, there's a way to use this feature just when it can be most helpful.
Stick with the normal scroll-by-page approach, but when you want to perform a hyperspace jumps to a specific location in a long document, Option-click in the scroll bar for a one-time jump to that location. I find this technique particularly useful in iPhoto, since scrolling around thousands of photos takes forever. I use Option-click to jump near the location I want, and then click normally to scroll the remaining short distance.
Application Drag and Space Scrolling
Look for alternate ways of scrolling in some applications by clicking and dragging, or by pressing the spacebar. These methods are common, but not universally supported. For instance, hold down Command-Option when using a Finder window in icon view, and you can then click inside the window and drag to scroll its contents.
In Adobe Acrobat (at least version 5.0), you can drag to scroll when using the hand tool, as long as either you're zoomed in to see less than a page at a time or your Display preferences are set to use one of the Continuous page layout options. You can also change this on a per-document basis from the View menu, if you prefer Single Page layout normally, but occasionally want to scroll by dragging. The same is true for Apple's Preview - choose Continuous Scrolling in the View menu to enable drag scrolling.
Don't like downloading a PDF just to see if it's something you might want to read more carefully? Try Manfred Schubert's PDF Browser Plugin, which provides PDF viewing in Safari and some other Web browsers. Why do I mention it in this context? Because it provides drag-scrolling of PDF files by default inside your Web browser's window. It also lets you save PDF files or open then in another PDF viewer like Acrobat Reader.
Lastly, don't forget the unassuming spacebar. Since the dawn of time (or at least the dawn of the keyboard), Internet applications that were primarily about reading text, such as email clients, Usenet newsreaders, and, later, Web browsers, have used the spacebar as a shortcut for scrolling down in long pieces of text. It works in Eudora, Mail (in the preview pane), Entourage, Safari, Internet Explorer, Camino, Preview, and many more. Less common is support for scrolling back up in documents; in Entourage, Mail, and Safari you can use Shift-spacebar; in Internet Explorer it's Option-spacebar. I can't guarantee that the specific applications you use for reading Internet content will support spacebar scrolling, but it's likely, and certainly worth investigating.
Scrolling, Scrolling, Scrolling
I'm not saying that you should put a lot of thought into how you scroll around in Mac OS X, just that with small amount of one-time effort, you can learn a few new tricks that make it even easier to use your Mac when you can't see the entire contents of a window at once.