$(function() {
    $('.rollover[data-hover]').mouseover(function() {
        var $this = $(this), originalImage = $this.attr('src');
        if ($this.data('imagesSwapped')) {
            return;
        }
        $this.attr('src', $this.attr('data-hover')).data('imagesSwapped', true);
        setTimeout(function(){
            $this.attr('src', originalImage).removeData('imagesSwapped');
        }, 200);
    });
});