Tip: Using the 'Command' key to organize background windows.

Various features of Mac OS X are quite convenient for work flow and window organization, especially when it comes to managing windows behind the foremost one. For instance, you can scroll the contents of a background window by hovering the mouse over it and using the scroll wheel or two-finger scrolling on Apple trackpads. You can also directly click the close, minimize, or zoom buttons on windows without bringing them to the front.

In addition to these features, more aspects of background windows can be controlled by holding down the Command key. This feature was introduced in the classic OS, but has been carried over into the current Finder as well and allows for several very useful functions, especially for those who clutter their screens with windows.

For instance, you can select or close different tabs in a Safari window, move a window around the screen that is currently behind others, and resize a window. You can also select and drag text from text fields and word-processing documents, and drag and drop items that are in the Finder to other locations, all without bringing the windows you're manipulating to the front. The universally shared functions for all windows are the moving and resizing of windows, but others such as the Safari tab-closing support are application-specific and will need to be explored on a per-application basis.

Unfortunately, in some cases such as with Command-selecting Finder sidebar items resulting in a new window being opened, Command-clicking may elicit another function that will switch focus of the window. However, for basic window manipulation and organization the use of Command-clicking can be exceptionally useful.

Resources