hoverIntent is a plug-in that attempts to determine the user's intent... like a crystal ball, only with mouse movement! It works like (and was derived from) jQuery's built-in hover. However, instead of immediately calling the onMouseOver function, it waits until the user's mouse slows down enough before making the call.
Why? To delay or prevent the accidental firing of animations or ajax calls. Simple timeouts work for small areas, but if your target area is large it may execute regardless of intent. Also, because jQuery animations cannot be stopped once they've started it's best not to start them prematurely.