"In general you want to use mouseenter and mouseleave instead of mouseover and mouseout"
http://www.quirksmode.org/dom/events/mouseover.html
"The mouseover event fires when the user moves the mouse onto an element. The mouseout event fires when the user moves the mouse out of an element. Unfortunately these events bubble up.
mouseover fires when the user moves the mouse over the element you registered the event on or one of its descendants. mouseout fires when the user moves the mouse out of the element you registered the event on or one of its descendants.
mouseenter and mouseleave are similar to mouseover and mouseout, but these events do not bubble.
In general you want to use mouseenter and mouseleave instead of mouseover and mouseout."
eg:
$('#panels li a').mouseenter(function() { $(this).find('span').animate({'top': '0'}, 'fast'); }).mouseleave(function() { $(this).find('span').animate({'top': '100%'}, 'medium'); });
