In Leopard, after activating Exposť in All Windows mode with the keyboard or mouse button, you can view all the window title overlays by holding down the Option key, instead of seeing them one at a time on mouseover.
[robg adds: Simple, undocumented to the best of my searching abilities, and very very useful!]
Here's a simple way to move your swap partition under Leopard that appears to work for both Intel and PowerPC based Macs. Edit the file com.apple.dynamic_pager.plist, located in /System/Library/LaunchDaemons. Replace the /var/vm path with the full path to your swap partition. In my case, the entire plist ends up looking like this:
Save and reboot, then check your new swap location is being used with this command:
ps -wax | grep dynamic_pager -m1
Finally, you probably want to clear out any old swapfiles from /var/vm:
sudo rm -rf /var/vm/swapfile*
As mentioned this works on PowerPC and Intel Macs, and it also works after reboot or shutdown/restart. However, if your swap partition can't be found, there is no fall back -- Leopard will start up without swap, and may get unstable if you continue to use it in that state. There's a more verbose version of this tip in this forum thread, with some extra discussion regarding the sizing of the swap files.
After moving some .sparseimages I created in Tiger to Leopard, upon mounting them, I noticed that Spotlight was not finding items that I knew existed on them. After turning off and re-enabling indexing for the volumes via Terminal several times with no luck, (and yes, I did wait long enough for Spotlight to finish the indexing process), I realized that if I created a new folder on the .sparseimage, it would show up in a search. However, none of the pre-existing files/folders would be found.
Then I tried renaming one of the pre-existing folders, and the new name showed up in a search. Then I renamed it back to the original name, and all was well. I also noticed that renaming only seems necessary for items on the top level of the disk, since any nested items I searched for started showing up in Spotlight after renaming the top folder.
[robg adds: I can't confirm this one, but if true, it seems like a bug. If anyone can test, please comment.]
If you Option-double click an event in your iCal calendar, it highlights the event's title immediately and lets you edit it, without bringing up the pop-up window. Not necessarily faster, but less intrusive.
Most of the items in your sidebar will appear in the open dialog in 10.5. One exception is the items under Search For, including your custom Saved Searches.
However, if you navigate to the ~/Library/Saved Searches folder (or any place you have Saved Searches stored) and drag the Saved Searches to the Places section of your sidebar, you can open (and even edit) saved searches from within the Open Dialog. Note that searches can appear in both the Search For section and the Places section at the same time; I dragged mine out of the Search For section, since they're more useful in the Places section.
Hidden in the Developer Tools package, there is a System Preferences panel that serves the same purpose as this hint about the CPU Palette.
After installing Xcode, navigate to /Developer » Extras » PreferencePanes, and then double-click on Processor.prefPane to install it. The Processor panel will add itself in the Hardware (not Other) section within System Preferences.
Using this panel, you can do everything you can do with the CPU Palette, minus the graphs but plus some L2 Cache and frontside bus info. The best part, however, is the fact that you can use the panel to add a menu bar item that replaces CPU Palette. From the menu bar icon, you'll have access to the preference pane, the option to use two or one cores, and the CPU Palette itself.
Time Machine can help you easily find the place in your backups when a file was changed. Start Time Machine and select a file in the Finder whose previous version you'd like to locate. If you put the Finder in List view, then you can see the preview for the file, including modified date (and version for an application).
Click on the big "back in time" arrow once to search through the list of backups. Time Machine will automatically stop at the point where the file was last changed. If you click the back arrow again, it will stop at the next previous change point. Likewise, the forward arrow scans towards the present for changes.
As an example, I applied the 10.5.1 update today. I started Time Machine and went into my Application folder and selected the Mail program. It showed version 3.1. I clicked on the back arrow, and I was taken immediately to the point where the program version was 3.0, just before the update had been applied.
Another thing I noticed is that if you Command-click one of the arrows, it takes you only one step through the backups, overriding the "scan for changes" behavior.
[robg adds: While I somehow know this is how Time Machine works (though I wasn't aware of the Command key override), I think it's because I saw it in an Apple presentation somewhere. I can't find any reference to this behavior in the Time Machine help file, nor on Apple's list of 300 new Leopard features.]
If you try to make a Web Clip widget of a small item on a web page in Safari, you may be dismayed to find that Safari limits you to about 128x128 pixels. As an example, I tried making a widget of just the text on the side bar of macosxhints.com that says, "nn new Hints in the past 1 day(s)," but I found that the smallest size I could make it was quite large compared to most widgets, and had a lot of grey space.
The solution is simple, if not obvious. After creating the widget, just click on the "i" on the widget and then click on Edit. You can then resize and reframe the widget so that you only see what you want to see.
When you are in Time Machine, you can press the red close button at the top left of the window being viewed to close Time Machine. When you do so, the window itself will not close, just Time Machine.
This is also useful if you have a slower computer and you want to cancel Time Machine while it is animating to the Space visual. You can press the close button on the window in question at any time during the animation, and it will revert back to it's pre-Time Machine position. You don't have to worry about the window closing.
Again, killall Dock to see your changes. Once the spacer is in the Dock, you can drag it around to move it. You can even drag it between the application and document sections, if you wish. Run either command multiple times to add multiple separators.
[robg adds: I tried this in 10.4, but it's definitely a 10.5-only hint, and it works as described -- the image above is from my machine. It seems this ancient hint can finally be retired (though the spacers are a bit wider than I would prefer, if I actually used the Dock much).]