Some of the changes in Leopard are obvious—Time Machine, Quick Look, Spaces, and so on. Others are more subtle. Here are some of our favorite tips and tricks for working with some of the lesser known new features in System Preferences and Terminal.
System Preferences
Reveal Login Items in the Finder – Ever wondered where some of those items in your Login Items list (in the Accounts preference pane) came from? In Tiger, you could hold your mouse cursor over an item to see its path. In Leopard, it’s even easier: just control-click on any login item and then choose Reveal In Finder from the contextual menu.—Dan Frakes
Easily Remove Third-Party Screen Savers – In Tiger, if you installed third-party screen savers and later wanted to remove one, you had to navigate to your user folder/Library/Screen Savers and then find and delete the unwanted plug-in. In Leopard, you can just go to the Desktop & Screen Saver preference pane, control-click on the offending screen saver, and choose Move To Trash from the contextual menu.—Dan Frakes 
Uncover Advanced Printer Options – In OS X 10.4, if you wanted to connect your Mac to a nonstandard printer, or to a standard printer using a nonstandard protocol (such as some PCL-only Windows-shared printers), you used the Advanced setup screen by clicking on the Add button in the Printer Setup Utility’s toolbar, and then option-clicking on the More Printers button and selecting Advanced from the pop-up menu. From there you could choose connections such as a FireWire printer, a Bluetooth modem printer, or a Fax Printer, among many others. In Leopard, that Advanced screen has moved to a more accessible spot, but it’s hidden by default. To reach it in OS X 10.5, first click on the plus sign (+) in the Print & Fax preference pane. When the next window appears, control-click on its toolbar and choose Customize Toolbar. When the customization sheet appears, drag the Advanced button into the toolbar, and click on Done. When you click on this new button, you’ll be presented with an advanced configuration pane.—Rob Griffiths
Access Print & Fax Preferences Directly from Some Programs – You probably already know that command-P is the generic shortcut for displaying the Print dialog box. But did you know that, in some programs, you can press command-P again, while the Print dialog box is on screen? What happens next—and whether this is a useful tip or not—depends on the program you’re using. In Apple’s Automator, Font Book, iChat, Mail, Safari, Script Editor, and TextEdit, for example, the second command-P will open the Print & Fax preference pane—a useful shortcut if you need to access that pane just before printing. In Preview, pressing command-P twice will actually print the current document.—Rob Griffiths
Copy and Paste Parental Control Settings – If you’re setting up multiple user accounts with parental controls, and the accounts will have similar settings, first set up one account. Then, in the Parental Controls list, select that account, click on the Action button at the bottom of the window, and choose Copy Settings For Account. Then, to apply those settings to another account, select that account, click on the Action button, and choose Paste Settings To Account. Even if you don’t plan on configuring each account exactly the same way, you can use this technique to copy a general set of settings and then edit them as necessary, rather than starting from scratch multiple times.—Dan Frakes
Reset the Printing System – Tiger’s Printer Setup Utility provided a Reset Printing System command that could often solve printing problems when all other troubleshooting techniques failed. But Printer Setup Utility is nowhere to be found in Leopard. Fortunately, Reset Printing System is still around; it’s just well hidden. To find it, open the Print & Fax preference pane, and then control-click on any printer in the Printers list; you’ll find the command in the contextual menu.—Dan Frakes 
Find Out What’s On – Sometimes when you have Universal Access turned on, your Mac will start doing strange things—using its display to impersonate an X-ray machine, reciting the name of the currently selected item, and so on. This is usually the result of a slip of the fingers combined with a Universal Access feature being mistakenly switched on. Leopard can help you quickly identify the problem. Open the Universal Access preference pane and enable the Show Universal Access Status In The Menu Bar option. That done, you should see a Universal Access icon in the Mac’s menu bar. Click on that, and you’ll see a list of Universal Access options and the current state of each—Mouse Keys On, for example. Note that this truly is a status menu: it shows only what’s on and off. To fix the problem, you’ll have to go back to the Universal Access preference pane.—Chris Breen
Terminal
Navigate Terminal Tabs – One of the most welcome new features in Terminal is the addition of tabs. Now, instead of having five separate Terminal windows open, you can have just one window containing five tabs. Creating a new tab is as simple as pressing command-T, and you can switch between tabs by pressing command-shift-[ (left bracket) and command-shift-] (right bracket). If you find those last two combinations awkward to remember and to execute, you can reassign them in the Keyboard Shortcuts section of the Keyboard & Mouse preference pane. But that’s time-consuming, and you’ll have to repeat it on each machine you use. Instead, try pressing command-shift and the left- or right-arrow key. These undocumented shortcuts are, for me at least, easier to use and remember than using the brackets. If you leave out the shift key, these shortcuts will cycle between open windows.—Rob Griffiths
Manage Terminal Tabs – Terminal tabs can perform many of the same tricks as Safari tabs. You can turn any tab into a new window simply by dragging it off the tab bar. You can rearrange tabs by clicking and holding on a tab, sliding it along the tab bar, and then releasing the mouse button; as you move one tab, the others will jump out of the way. You can also merge multiple windows into one tabbed window. If you have many open windows and want to combine them all, just use the Window: Merge All Windows menu command. If you’d rather be more selective about which windows get merged, you can drag and drop a stand-alone window into the tab area of another window. (For this trick to work, the tab bar must be visible in both windows.) To set the tab bar to be always visible, use the View: Show Tab Bar menu item.—Rob Griffiths
Customize the Command Line – In previous versions of OS X, you’d see a “Welcome to Darwin!” message whenever you opened a new Terminal window. In OS X 10.5, though, all you’ll see is the date and time of your last new Terminal window. If you’d like the old welcome message back—or any other welcome message, for that matter—open Terminal and enter cd /etc, press return, and then type sudo pico motd. That second command launches a text editor and loads a new file called motd (Message Of The Day). Type whatever you like for a message (for instance, “Welcome to the land where text is king”), press control-X (for Exit), press Y (for Yes, to save changes), and then press return (to accept the file name, which will be shown as motd). From now on, new Terminal windows will display your new greeting, right below the date and time of the last login.—Rob Griffiths