Drop down menus allow users to explore deeply into a site without being overwhelmed with a lengthy list of links. Sadly, these elements can frustrate users when following a trail of panels becomes a game of dexterity. They can also be inadvertently triggered by a stray mouse, blocking content. HoverIntent, by Brian Cherne, is a jQuery plugin that interprets users intentions. Adding small delays on triggering and hiding events, prevents accidental movements. Being light weight and easy to use, I will personally begin adding it to my toolkit.
