First of all, allow me to apologize for that title. There really is no better way to describe in a concise way what hoverIntent does. HoverIntent is a jQuery plugin that helps you capture mouse events only when your user intends to have them fire.
There is an example available for this demonstration that is available at: http://www.learnjquerynow.com/demos/hoverIntent.php. You will want to look at the source to see how everything is done.
The most ideal problem this plugin solves is having complex menus for your website to show and hide in a way that is very smooth and natural for the user. You can have menus only appear and disappear only when you are sure that is what your user wants to do.
This is without a doubt a plugin that you do not want to forget about. It is just too helpful to not have in your toolkit.