Prior to 10.7, to remove an icon from the Finder sidebar was as simple as dragging the icon off the sidebar and letting go, watching as the icon disappeared with a ‘poof!’
In Lion, you can remove icons in a similar fashion, but now you must hit the command (⌘) key before letting go of the icon; otherwise the icon will simply snap back onto the sidebar.
As with prior versions of Mac OS X, you can also right-click the icon and select “Remove from Sidebar.”
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