Here’s a sampling of Leopard-themed hints provided by the readers of MacOSXHints.com. Whenever possible, we’ve used the real names of the users who provided the hints. In some cases, when they prefer anonymity, we’ve used their screen names instead.
Faster Screen Sharing
You probably know that you can share screens with another Mac from iChat and the Finder. But a more powerful tool for this purpose, cleverly named Screen Sharing, is hidden in /System/ Library/CoreServices. When you launch it, you’ll see a dialog box asking for the network address of the remote machine. If you don’t know the IP address, quit Screen Sharing, switch to Terminal, and type (all on one line):
defaults write com.apple.ScreenSharing ShowBonjourBrowser_Debug 1
Now launch Screen Sharing again and revel in the new Bonjour Browser window, where you can pick the machine to which you’d like to connect. You’ll still have to supply a user name and password, but at least you don’t have to enter the full network address. If you want to make future access a bit easier, select Add To My Computers to add that machine to the Bonjour Browser window.—Christopher Aloi
Power up Screen Sharing
You can add some hidden functionality to the Screen Sharing tool. Quit Screen Sharing, switch to Terminal, and type the following (all on one line; type a space at the end of each of the first five lines, but not after Curtain, or GetClipboard, ):
defaults write com.apple.ScreenSharing 'NSToolbar Configuration ControlToolbar' -dict-add 'TB Item Identifiers' '(Scale,Control,Share,Curtain,Capture,FullScreen,GetClipboard,SendClipboard,Quality)'
When you relaunch Screen Sharing, you should see five new buttons and a slider on your toolbar. (If you can’t see the toolbar, use View: Show Toolbar to make it visible.) See “Customize Screen Sharing” for a rundown of what each button does. These features don’t always work flawlessly, but for the most part they run just fine. You can customize the toolbar as you wish—for example, use Command-drag to rearrange icons.—Dennis Wilkinson and Daniel Steffen 
Quickly clear Stacks
Leopard’s stacks have met a mixed reception, but I’ve found that I can increase my productivity by creating a Working stack for projects I am currently working on. (First I create a Working folder in my home directory, and then I drag it to the Dock). When I start to work on a project, I drag aliases for all the relevant files into that Working stack (by holding down Command-option as I drag the files to the Dock). I then have quick access to all my current files.
While that Working stack helps a lot, it’s annoying to have to empty it whenever I finish or switch projects. To fix that, I created an Automator workflow that clears all the files in the stack:
1. Files & Folders: Get Specified Finder Items Specify the Working folder you created in your home directory.
2. Files & Folders: Get Folder Contents
3. Files & Folders: Filter Finder Items: Name Is Not Equal To Clear Working.app
4. Files & Folders: Move Finder Items To Trash
I then saved this workflow as Clear Working.app and put it into the Working stack itself. Whenever I finish a project, I open the stack and double-click on the Clear Working workflow.—Andrew Wagner 
Speed up Folder Actions
Folder actions—scripts you can attach to specific folders—have been available in OS X since version 10.2. In Leopard, a Folder Action Dispatcher program triggers them, checking for modifications in a folder at a specified interval. Unfortunately, the default interval is 180 seconds, which can sometimes be way too long. Because Folder Action Dispatcher is scriptable, you can change that interval. Open Script Editor (/Applications/AppleScript), and type the following (all on one line): tell application “Folder Action Dispatcher” to set polling interval to x . Replace x with your desired polling interval in seconds. Click on the Run button in the toolbar, and voilà.If the Script Editor asks where Folder Action Dispatcher is, browse to /System/ Library/CoreServices/.—steff-x2
Monitor your CPU cores
Activity Monitor’s CPU pane is nice, but if you want a bigger picture of what’s going on inside your Mac’s CPU, navigate to /Library/Application Support/HWPrefs and launch the CPUPalette program. (If you don’t find it there, insert your Leopard install disc, click on Optional Installs, select Packages, and double-click on CHUD.pkg; that will install CPUPalette.) It will display two graphs showing how busy your CPU’s cores are, and let you disable one or more of them. Click on the oblong button in the upper right corner to reveal a settings panel where you can adjust transparency, sample interval and history, and chart format. You can drag the program to your Dock, sidebar, or toolbar for fast future access; to quit it, click on the red close button.—semaja2
View plists in Quick Look
At some point in OS X’s evolution, Apple began saving plists in a binary format instead of in XML. That was a pain if you just wanted to look quickly at preference settings. You either had to convert the file to XML using plutil or open the file in Property List Editor, which is a poor browser. But in Leopard, Quick Look displays binary plists as XML. You can select a bunch of plists, launch Quick Look, and view all of them using Quick Look’s simple navigation tools.—Jeffery Parks
Secret Screen Savers
If you’re tired of Leopard’s built-in screen savers, a slew of Quartz Composer compositions hidden in the System folder can add visual variety to your Mac’s dozing screen. To try them, first quit System Preferences if it’s running. Go to /System/ Library/Compositions and drag as many of these files as you like from there to your user folder/Library/Screen Savers. (Create this folder yourself if it doesn’t already exist.) Not all of these Quartz compositions will work as screen savers. In general, if you can see a moving image in the Finder’s preview pane, the file should work. I’ve found that Defocus.qtz, Fall.qtz, Grid.qtz, Image Hose.qtz, Moving Shapes.qtz, Travelator.qtz, and Wall.qtz work quite well. Once you’ve copied the files, open System Preferences, select Desktop & Screen Saver, scroll down to the Other section of the left pane, and select a new screen saver. Clicking on the Options button will let you tweak the settings on some screen savers.—datasmid
Clean up the ‘Open With’ menu
Sometimes when you control-click on a file to use the Open With contextual menu, you’ll see double entries in the list of available programs; you may even see programs you know you’ve removed from your Mac. What you need to do in that case is rebuild the LaunchServices database. To do so, open Terminal and type (all on one line; there should be no spaces between characters until -kill ):
/System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/LaunchServices.framework/Versions/A/Support/lsregister -kill-r -domain local -domain system -domain user
Once you’ve rebuilt the database, the list of available applications should be dupe-free.—Jan Verbeke