This tutorial is about the favorites section available in the Finder component on Mac OS X Lion. For example if you are not using the Air Drop feature available in new Mac OS X Lion then you can hide the item from the favorites section.
Click the Finder menu and select Preferences from the menu list.
In the Finder Preferences, navigate to Sidebar tab and un mark the check box with label as AirDrop available under FAVORITES.
By this way you can hide the favorites item on Mac OS X Lion. Similarly you can unhide any item by marking the check box related with the favorites item under Preferences.