I am a bit stuck with this one. Here is a basic outline of my setup:
<div id="shell">
<div class="subelement">One</div>
<div class="subelement">One</div>
<div class="subelement">One</div>
<div class="subelement">One</div>
</div>
While this question already has an answer, an additional answer was provided that I tweaked and has since been deleted. Here it is using jQuery and loses the hover state when nothing is hovered. Easy.
$(".subelement").hover( function() {
$(this).siblings().stop().fadeTo("fast", 0.5);
}, function() {
$(this).siblings().stop().fadeTo("fast", 1.0);
});