Like many people these days, I work from my home, though lately I've been spending more time protecting my possessions from a pair of unruly kittens. Kittens or no kittens, I don't have much face-to-face interaction with Mac users while I use my computer. Recently, however, I was fixing a problem on an acquaintance's machine. Every few minutes she would interject "Wait - how did you do that?" or "Hey, that's neat!" I wasn't performing magic, but there are techniques that newer Mac users - even those who use Macs full-time - haven't found. After all, they're trying to do work, not become computer experts. Here, then, is a non-comprehensive list of not-necessarily intuitive techniques for the Finder and file dialogs. Except where noted, these all work with System 7.x and Mac OS 8; I hope you find them useful.
Keys to Finder Windows -- Many users never go beyond using the mouse to open an item by double-clicking it, then clicking the window's close box to close it. All that mouse-waving can be awkward and time consuming. It's possible - and faster - to do almost all your Finder navigation from the keyboard.
You can select a single item on the desktop or in the active Finder window by typing the first few characters of its name, or pressing Tab until the item is selected (if you tab past the item you want, press Shift-Tab to back up).
The left, right, up, and down arrow keys can also be used to select items in the Finder's icon and list views, moving the selection one item at a time through a window. In long list views, you can quickly jump to the top and bottom of the list by pressing A and Z or Home and End; also, the Page Up and Page Down keys scroll a Finder window vertically (great for list views, but not as useful in large windows using icon views).
Once you've selected the item you want, the Command key and the arrow keys become your best friends. Pressing Command-Down arrow opens the current selection, whether it's a folder, document, or application. If you press Option at the same time, the Finder window containing that selection closes after the item opens, reducing window clutter.
If you're already in a folder window, pressing Command-Up arrow opens its parent folder, and (like before) pressing Command-Option-Up arrow closes the previous window after opening the parent folder. If you're in a Finder's list view, Command-Left arrow and Command-Right arrow respectively open and close the hard-to-click "discovery triangles" that appear next to folders, allowing you to access their contents without opening a new window. You can then select an item in a sub-folder using the arrow keys, the Tab key, or by typing the item's name.
Here are two little-known tips. To switch the focus from a Finder window to the desktop, press Command-Shift-Up arrow: the desktop becomes active and your startup disk's icon will be selected. (Unfortunately, using the Option key with this combination doesn't close the current Finder window.) Want to close every Finder window? Press Command-Option-W, and the Finder closes every window in succession.
What can't you do from the keyboard? As far as I know, there's no way to select multiple items in the Finder using just the keyboard (the equivalent of Shift-clicking or Shift-dragging), and there's no built-in way to directly move to another open Finder window (the equivalent of clicking any visible portion of that window), although some third-party utilities offer that functionality.
To Arrow Is Human -- The arrow keys are also best friends in those awkward Open and Save dialogs - called standard file or SF dialogs - that appear in most applications and are almost unchanged since System 6. (Mac OS 8 includes the foundations for improved "Copland-like" Open and Save dialogs; hopefully, programs will take advantage of them soon!) By themselves, arrow keys move you up and down the list of items displayed in the SF dialog (if the list isn't active, press Tab to switch between the list and the text field where you name a file). You can also press letters, Home, End, and the Page Up and Page Down keys to move through an SF dialog's list.
Pressing Command in conjunction with arrow keys in an SF dialog works almost exactly the same as in the Finder: Command-Up arrow opens the parent folder, Command-Down arrow opens a sub-folder (but won't open a file), and Command-Shift-Up arrow takes you to the desktop (as does pressing Command-D, or clicking the Desktop button).
However, pressing Command-Left arrow or Command-Right arrow moves you between volumes, rather than folders, which can be handy if you have multiple hard disk volumes or regularly use removable media or file servers.
Power To the People -- And what about that Power key that's on almost every Macintosh keyboard? Generally it's marked with a triangle, and it's good for more than turning on your Mac. Under Mac OS 7.5 and higher, if you press the Power key while your Mac is on, you'll see a dialog asking if you want to restart, shutdown, or (if possible) put your Mac to sleep. You don't have to click any of these buttons: pressing R selects Restart, and pressing S selects Sleep, if available. (Of course, pressing Command-period or Escape selects Cancel, which should be true of every dialog box with a Cancel button).
Unfortunately, pressing Command-Power is a substitute for a physical "programmer's switch" that used to be included with older Macs. If you have a debugger installed, pressing Command-Power triggers it; otherwise, you get a dialog containing just a > character. This occurrence is all too common for PowerBook owners using Mac OS 8, where pressing Command-Delete moves items to the Trash. On many PowerBooks, the Delete key is immediately below the Power key. If you see this dialog, your best bet is to press g (which stands for "Go") and Return. Most of the time - though not always - this will restore your Mac to its previous state.
Windows users often scoff at the Mac because you can't do everything from the keyboard, and although can't control every application entirely from the keyboard, if your fingers learn these tricks, you'll navigate the Finder like never before.