Here’s a simple and welcomed change in OS X 10.5. As you’re probably aware, the icons (and nearby text) in the top (title) bar of many OS X windows can be Command-clicked in order to view a drop-down menu showing the path to the currently-active document.
In TextEdit, for instance, Command-click on the icon in the title bar of a document’s window, and you’ll see the full path to that document’s save location. Select one of the folders on the path, and that folder will open in the Finder. In Safari, you’ll see the “path” to the current page from the root of the web site; select one of the other entries in the list to load that page in the browser.
The simple change in 10.5 is that these icons can now be Control-clicked as well as Command-clicked. So if you’ve got a multi-button mouse (and if you don’t, you should go get one—really!), you can make the drop-down menu appear with a click of your right mouse button; no need to hold a key on the keyboard and use the mouse at the same time. As much as I try to keep my hands on the keyboard, if I have to reach for the mouse, it’s definitely nicer being able to just reach for the mouse.