cduruk's solution was quite effective, but caused problems on a few parts of my site. Because I was already using jQuery to add the CSS hover class, the easiest solution was to simply not add the CSS hover class on mobile devices (or more precisely, to ONLY add it when NOT on a mobile device).
Here was the general idea:
var device = navigator.userAgent.toLowerCase();
var ios = device.match(/(iphone|ipod|ipad)/);
if (!(ios)) {
$(".portfolio-style").hover(
function(){
$(this).stop().animate({opacity: 1}, 100);
$(this).addClass("portfolio-red-text");
},
function(){
$(this).stop().animate({opacity: 0.85}, 100);
$(this).removeClass("portfolio-red-text");
}
);
}
*code reduced for illustrative purposes