Move Background Windows While Keeping Them Out of the Foreground in Mac OS X
Want to shuffle around some windows in the background without bringing them into the foreground? Hold down the Command key, and then click on a windows titlebar, the window can now be moved and dragged around in the background without bringing it to the foreground. This should work in all versions of Mac OS X.
This is a great little trick to clear the view for other apps or the desktop. Try it out yourself or see the brief video below for a demonstration of how it works.
Thanks to Josh F. for sending in the tip