Don't wait for Snow Leopard—slim down, speed up Leopard now
4. Clean out logs
I mentioned this one in my recent list of tips for keeping Leopard purring, but it's worth mentioning again. Log files are generated by a number of Leopard's processes as well as by applications, which may maintain their own logs or record items to Leopard's system.log file.
Leopard's maintenance scripts automatically archive and compress log files on a regular basis. Even so, the number of archived log files can grow rather large. If you do not have a need to keep archived logs dating back weeks, months or even years, then you can remove some of these older log files to recover some disk space.
Systemwide logs (those that record events from system components and applications that impact all users of a computer) are typically stored in the /Library/Logs folder at the root level of your start-up drive, and user-specific logs are stored in the /Library/Logs folder inside each user's home folder.
5. Delete unused applications and tools
This one may seem like a no-brainer, but it's worth mentioning because it's easily overlooked but can really affect performance. Deleting unused applications (including those that come with Mac OS X, those that come with other commercial suites or shareware apps you've downloaded but never really used) alone can save a lot of disk space.
So can removing unused system components such as screen savers, preference panes for System Preferences and Dashboard widgets. Since your Mac needs to load many of these items at start-up/log-in or when launching Dashboard, you can see performance as well as space-saving gains by trimming down the add-ons that you don't use.
System components are typically stored in the Library folder in your home folder (if installed only for your user account) or at the root level of your hard drive (if installed for all users). A similar set of items that take up space is unused printer drivers, though these are more safely and easily removed using the Print Therapy utility ($30) than by hand for most users.
In addition to removing the actual application and component files, you should remove the supporting files and preferences files. These can often end up taking up more space than the application itself. Applications typically create support files in the Library/Application Support folder in your home folder or at the root level of your hard drive, where they store a variety of different files that are needed to implement functionality. (iWeb, for example, stores every Web page and related file that you create in this folder, which can take up huge amounts of space.) Preferences files rarely take up as much space but are worth removing as well.
Some applications also create folders at other locations in the Library folder(s). So, taking a quick look for anything that looks specific to a deleted application can help eliminate space as well.
If performing this process by hand seems a little too complex or time-consuming, AppZapper ($13; free trial) is a great inexpensive utility that ensures that when you delete an application, all of its supporting files go with it.
AppZapper can be used to locate and remove third-party preferences panes and Dashboard Widgets as well.
6. Reduce log-in items
This tip takes on performance rather than disk space. You can often speed up Leopard's initial log-in time, as well as some of its overall performance, by limiting the number of Login items.
Login items, which can include applications and helper processes for system components and apps, launch automatically and typically continue to run in the background while you're working. Often log-in items are installed along with an application without your knowledge. Some of these may be needed for the application to function properly, but not all.
Also, not all Mac users may need access to log-in items installed by every application. You can speed up things for other users by removing log-in items that they don't need from their user accounts.
To stop apps from starting up when you log in, go to the Accounts pane in System Preferences and click the Login Items tab. Then select the log-in item you want to remove and click the minus button beneath the list of log-in items. (If the Hide box next to a log-in item is checked, it will still launch at log-in, but you will not see any indication of it launching; this is typically the case for helper applications or processes, such as the iTunesHelper application.)
If you later discover that removing a log-in item creates problems with an application or component, launching the item manually often resolves the issue, and some helper processes will automatically launch when their associated applications are started. To restore a log-in item permanently, you can locate the file on your hard drive and drag it back into the list box, or use the plus button to add it through a file open dialog. This is the same approach you would use to add additional log-in items.
7. Do without the 3-D effects and animation
Leopard's interface sports many 3-D and animated effects. From the 3D Dock with its Stacks icons, to the optionally translucent menu bar, to a number of Finder animations that were originally introduced in Tiger, Leopard is chock full of high-end graphics goodness. Of course, those fancy graphics require rendering power. This can make Leopard seem sluggish on some older Mac models.
One solution to this problem is to disable some or all of these effects. You can revert to Tiger's 2D Dock using tools such as TinkerTool (free) or LeoColorBar (free), turn off the translucent menu bar using the Desktop & Screensaver pane in System Preferences, and display folders in the Dock as folders rather than Stacks (control-click on each folder in the Dock and choose Display as Folder). You can also disable animation effects in the Finder (as well as adjust several other system variables) using TinkerTool.