Pity the unassuming workhorse of the keyboard: the Tab key. Even the Shift key gets more respect. But just because it's unpretentious, you shouldn't assume it does nothing more than adjust indents in a word processor: the Tab key has a few tricks up its metaphorical sleeve. These tricks all work in Snow Leopard and may work in Lion too, unless otherwise noted.
1. Select items alphabetically in Finder windows
In Finder windows, in all but Column view, pressing the Tab key selects the next file alphabetically. You may not have noticed this because so many windows are already sorted alphabetically, so it seems that Tab merely selects the "next" file. But you can sort window contents by Size, Kind, Date, and so on by clicking a column header or choosing from the View -> Arrange submenu. (It might be a good idea, for instance, to sort your Downloads folder by Date Modified.)
No matter how the window's contents are sorted, you can always access the next alphabetic item by pressing Tab, with Shift-Tab selecting the previous alphabetic file. (This works even with a Lion window grouped into categories with the Arrange By menu: the Tab key jumps around to different groups as necessary.)
2. Navigate with your keyboard
If you like to keep your hands on your keyboard, you can use the Tab key to move from one window element (buttons, pop-up menus, text fields and so on) to another. The recent story "How to use your Mac without a mouse" describes how to turn on this feature in Keyboard preferences. But when you turn on that setting, you'll often find yourself tabbing through every control in every window, often wasting more time than you save. Tabbing to every element in a dialog box can be handy, but on a webpage it could drive you crazy.
So, turn this feature on and off as needed without repeated trips to the preference pane by enabling the Change The Way Tab Moves Focus shortcut. In System Preferences, open the Keyboard preference pane and click the Keyboard Shortcuts tab. Select Keyboard & Text Input in the list on the left; on the right, check the box in front of Change The Way Tab Moves Focus.
To change the default shortcut, double-click on the existing one and press the new key combo. I use Control-Shift-Tab—it's easy to remember because it controls the way you change—or shift—the Tab key Function.
3. Hop around all parts of a Safari window
It's easy to navigate mouse-free in Snow Leopard's Safari 5. When you have Keyboard Shortcuts preferences set to the default Text Boxes And Lists Only, pressing Tab cycles you from the address field to the search field, and through any fill-in fields on the web page. Safari also has its own setting for tabbing to elements other than fields. Go to Safari -> Preferences, click the Advanced tab and select the Press Tab To Highlight Each Item On A Webpage option. While this is handy because it selects clickable items such as buttons that you can then trigger by pressing Return, it doesn't let you get at Safari-window elements: toolbar buttons, the Bookmarks bar, or your tabs.
Forget the Safari preferences and head back to OS X's Keyboard Preferences. There, turn on the All Controls option for the Tab key. With All Controls on, first activate either Safari's address field (Command-L) or search field (Command-Option-F) to focus its attention on the title bar. Then press Tab or Shift-Tab to move through items in the Toolbar, Bookmarks bar, and Tab bar. When an item is selected, press the spacebar to activate it. When a menu is activated (such as one for a bookmark folder, or the More symbol (») for extra bookmarks or tabs), press the spacebar to open it, use arrow keys to highlight an item, and press Return to choose it. Pressing the spacebar closes a menu without selecting anything.
4. Switch applications in Exposé
(Image Caption: When Exposé is activated, pressing Tab opens the Dock, highlights your next open application and shows all its windows.) When you trigger the Application Windows feature of Snow Leopard's Exposé (F10 or Fn-F10 by default), you see all the windows for your current application—a great way to overcome the problem of moving to a specific window on a cluttered screen. If you want to view windows for another open application, press Tab while the current application's windows are displayed.
The Dock appears with the next open application highlighted against the darkened Exposé background and its windows displayed. Keep pressing Tab to move to other open applications in turn; as usual, Shift-Tab moves you in the opposite direction. You can do this application tour even if you've started with the All Windows Exposé option (F9 or Fn-F9 by default): pressing Tab switches you into the Application Windows mode and moves you to the next application. To switch to a displayed application, click in one of its windows (or select a window with Arrow keys and press Return). To return to the original application, press Esc.
5. Change a heading level in outline mode
Both Microsoft Word and Pages '09 provide an Outline view that lets you collapse your long document into easy-to-review headings of various levels. You don't have to apply a heading paragraph style, however, to change the level of a heading: with the text cursor anywhere in the heading (while you're in the Outline view), press Tab to demote it to a lower-level head—Heading 1 to Heading 2, for instance. Shift-Tab promotes the heading up a level.
6. Hide tool palettes in Adobe programs
The plethora of palettes in Adobe's Photoshop, InDesign, and Illustrator are a wonder on a big monitor, but a necessary nuisance on a laptop's limited screen real estate, where they tend to block parts of the document window no matter how you try to dock them. For an unobstructed view of your work, banish all the palettes instantly with a press of Tab; another press brings them back. (If you're working in a text box, first press Esc to deselect it so that the Tab isn't typed into your text.)
This story, "Six unexpected uses for your Mac's Tab key" was originally published by Macworld.