You've probably got the basics of the Application Switcher down pat by now: press Command-Tab to see a bar full of running-application icons and keep Command down as you tap the Tab key to quickly switch to the application of your choice. But, as with everything on the Mac, the Application Switcher can do more than you might guess.
One note: unless you're simply moving back and forth between two programs, press Command-Tab and then let go of Tab immediately to keep the Application Switcher on the screen. This lets you see where you're going, and approach more complex tasks, without the focus racing from one application icon to the next on the bar.
1. Quit all open applications
Say you want to install new software that requires you to quit all your programs. There's no need to move to every program and quit each individually. Press Command-Tab for the Application Switcher and then, keeping Command down, press and hold Q. Each application quits in turn; you'll be notified if there are any unsaved changes in documents.
2. Open a new window
Just as nature allegedly abhors a vacuum, users abhor a window-less application—after all, what can you do if there's nothing to work in? If you've left an application (Microsoft Word, for instance) with all its windows closed or minimized, you can use the Application Switcher to return to it with a window ready for you to work in.
Command-Tab to the program in question and, before you release the Command key, press Option. Release the Command key first, and then the Option key. (It's easier if you use the Option key on the opposite side of the spacebar instead of the one next to the Command key.) If the target program's windows are all minimized, the most recently minimized one returns to duty. If no windows at all are available, a new one is created. (Some programs interpret "new window" a little differently; Numbers, for instance, opens its Template Chooser for you to select from.)
3. Open a document in a different program
When you want to open a document in something other than its default application—a Word file in Pages, say—you can use variations of the Finder's Open With command. But if the target application is already open (and can handle the document), you can also just drag the file from the Finder onto the Application Switcher bar. The trick is to start the drag operation, and pause it with the mouse button held down, before you press Command-Tab; keep Command down so the bar stays on the screen, and drag the document onto an application's icon.
4. Bypass the Clipboard
You select a swath of text from a Word document to transfer to a document in InDesign, and realize you can't Copy and Paste because you'll lose what's already on the Clipboard. You can transfer the selection using the Application Switcher instead.
Start dragging the selection in the Word document (move it a little bit and then stop). With the mouse button still down, press Command-Tab. Holding Command down to keep the Switcher open, drag the selection into the InDesign icon. You'll be switched to InDesign, where you'll see the usual "ghost" of a dragged selection, just as if you were dragging it within the InDesign document itself. Drag it into position and let go of the mouse button.
The target window isn't frontmost in the destination? Hang on to the selection by keeping the mouse button down, and press Command-~ (tilde) to cycle to the correct window. You can also use Command-N to create a new window as a drop target.
5. Hide and show background applications
You're in Pages. You can see only Finder windows in the background, and you want to refer to a Stickies note. You don't have move to background applications to rearrange windows or to hide them as you leave. Instead, press Command-Tab to open the Application Switcher, tab to highlight the Finder, and, with Command still down, press H to hide the Finder's windows. When you release the Command key, you'll still be in Pages.
Unhiding a background application is a little tricky because if you repeat this procedure (in this case, tabbing over to the Finder and pressing H), the background windows will reappear, but you'll also be switched into that application when you release Command. To make the windows reappear while keeping your Mac's focus in the current application, you need to press Command-Tab, tab to the application icon, press H to unhide its background windows, and then press Esc while the Command key is still down. Release the Command key and you'll still be in the original application.
6. Jump to an alphabetical Exposé
You can quickly trigger Exposé when the Application Switcher is on the screen by pressing the Up or Down arrow; you'll see the windows for whichever application was highlighted in the Switcher bar.
If you know the trick for arranging Exposé windows alphabetically—pressing Command-1—you'll be pleased to know you can jump right to this alphabetical arrangement from the Application Switcher. Instead of using the Up or Down arrow key to open Exposé, highlight the application you want and press the 1 key (you're already holding down the Command key). Hold it down for a couple of seconds. What's happening is that Exposé is triggered, and then it notices that Command-1 is being pressed and so offers the alphabetical arrangement—you'll see the windows swap into correct positions.
Bonus tip for trackpad users
Are you a Magic Trackpad or MacBook user? Once the Application Switcher is on your screen (you must keep the Command key down), you can use your trackpad to navigate and select something from it.
The most obvious way is to use your finger to move the cursor to select an application and click it. A less obvious, but quicker way to navigate a long Application Switcher bar is to use a two-finger swipe when it's open: applications are quickly highlighted in turn, and the selection wraps when you reach either end of the bar. Pressing Return moves you to the selected application, while your cursor remains in the position where it started, instead of, perhaps, at the far edge of your screen.
If you're working on a late-model Mac, you have an additional, handy option: a 4-finger horizontal swipe opens the Application Switcher and highlights the previous application as the default. With the bar open, you can use the other swipe gestures to select and move to an application. A tap or a press of Return switches you to that application; a second four-finger swipe, or a press of Esc closes the Switcher. Turn on this option using the Trackpad pane in System Preferences.
Long-time Mac writer Sharon Zardetto remembers the thrill of the Mac's first Switcher program, by Andy Hertzfeld.
This story, "Six unexpected uses for your Mac's Application Switcher" was originally published by Macworld.