Have you ever wanted to perform some operation on the desktop, only to find that open applications' windows keep getting in the way? This happens to me a lot - usually when I've saved a document to the desktop and want to drag it to the appropriate file server.
Paul Lucas of Marrickville, NSW, e-mailed me the coolest tip for clearing clutter: with the application switcher (either as a palette or as a menu) you simply hold down the option key while selecting an open application (including the Finder) and all other applications' windows vanish. Presto!
I also get frustrated by some of the features Apple has built into the Mac to make life easier - Mac OS Easy Open and the Internet control panel, for instance. I don't always want to open a file using the application that I've set as a default.
Here's a neat trick, though: drag any file onto an application's button in the application switcher palette, and that application will attempt to open the file.