Everyone knows the problem, working with multiple programs at the same time and eventually having so many windows open that it's easy to lose track.
Mac OSX has a solution ready for this problem: Exposé.
You can easily control Exposé using the function keys on your keyboard. Pressing F9 will show you thumbnails of all open windows, F10 will show only those of the currently open program, and by pressing F11 all windows will be hidden, giving you an overview of your desktop.
Another tip from me: You can also control Exposé using the "active corners", meaning moving the mouse to a corner of your screen. You can customize which corner is assigned to which function under System Preferences -> Exposé / Spaces -> Exposé -> Active Corners. Have fun!
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