Navigating through the columns of an open or save dialog box can take a long while, especially if the location you are looking for is hidden deep within multiple folders.

Instead of painfully clicking through each level, you can just drag the folder from the finder straight into the dialog box. The open/save dialog instantly changes to display the contents of the folder you just dropped on.

Obviously you can use all the usual tricks with this, like Command-Tab to switch over to the Finder and back again, and exposé to find the window you want, but there are also a few extra quirks. For example, dragging any file to the dialog will display the enclosing folder, and you can also drag the folder icon from a Finder window's title bar.