Today’s tip came up recently in a discussion in the forums, and I thought it might be worth sharing for any of you who (a) migrated from OS 9, and (b) prefer to use Command-N to create new folders. In OS X, Apple assigned Command-N to the New Window command and Shift-Command-N to the New Folder command. Users who relied on keyboard shortcuts in OS 9 found the change quite shocking, as years of muscle memory resulted in new windows when they instead wanted a new folder.
For many of us, myself included, the new assignments made sense. With the presence of the new column view window mode, I found myself creating new windows more often than I created new folders. However, I can see how this change would be tireseome for those coming from OS 9. So here’s one way to resolve the issue, using nothing more than the tools built into OS X 10.4 (this trick will not work on 10.3). When you’re done, Command-N will once again create a new folder, and Shift-Command-N (or some other shortcut) will open a new window.
Open the System Preferences application, activate the Keyboard & Mouse pane, and then click on the Keyboard Shortcuts tab. We’re going to use OS X’s built-in ability to create shortcut keys to change the behavior of Command-N. You might not think this is going to work, since Command-N is already assigned to another command. But if you change the existing Command-N shortcut to something else, then you can easily assign the now-vacant Command-N to anything you’d like. Note that you can use this trick to reassign any existing shortcut, not just Command-N. Here’s what you need to do.
First, click the plus sign (at the lower left of the window) to add a new shortcut. In the new dialog that opens, set the Application to Finder, the Menu Title to New Finder Window, and then set the Keyboard Shortcut to whatever you’d like—Option-Control-N, for instance—as long as it’s not Command-N. With everything filled in, it should look like this:

Click Add to create this new (redefined, actually) shortcut. Now that Command-N has been freed from the New Finder Window command, you can reassign it to the New Folder command. Click the plus sign again, set the Application to Finder, the Menu Title to New Folder, and the Keyboard Shortcut to Command-N:

Again, click Add to finalize this shortcut. Close the System Preferences window, and switch back to the Finder. To make your changes take effect, you need to restart the Finder. You can logout and login again, or use a Terminal solution if you wish. But here’s an easy way to do it. Press and hold the Option key, then click and hold on the Finder’s Dock icon. When the contextual menu appears, select Relaunch, and the Finder will restart. If everything worked, you should see your newly-defined commands in the File menu:

The last step, and it’s completely optional, is to reassign the New Finder Window command to Shift-Command-N, completing the swap of the two keystrokes. You can’t do this in one step, since you must have one of the keyboard shortcuts undefined in order to assign it to the other command. The newly-created keystroke will work just fine, of course, but it’s easy to assign back to Shift-Command-N, if you so desire.
Open the Keyboard Shortcuts tab of the Keyboard & Mouse System Preferences panel again. This time, though, don’t press the plus sign. Instead, scroll the window down, until you see the Finder entry in the Application Keyboard Shortcuts section. Click the disclosure triangle next to Finder and you’ll see the two commands you created. Click on the shortcut next to the New Finder Window entry, then type Shift-Command-N. Quit System Preferences and relaunch the Finder again to make the newly-assigned shortcut effective. Presto changeo, you just swapped two existing keyboard shortcuts around.
If you find that you actually prefer the standard OS X behavior, it’s easy to get back. As above, find the two Finder entries you created. Highlight one and press the minus sign to delete it. Repeat with the second command, restart the Finder, and that’s it—you’re back to a stock setup.
Editor’s note: Story updated at 9:18AM on Tuesday May 16th to reflect that the tip only works in 10.4