jquery.linkheight.js

$.fn.linkHeight = function(target) {
  var el = $(this);
  target = $(target);
  var padding = parseInt(el.css('padding-top'), 10) + parseInt(el.css('padding-bottom'), 10);
  
  function updateHeight() {
    el.height('auto');
    var targetHeight = target.outerHeight() - padding;
    if (targetHeight > el.height()) {
      el.height(targetHeight);
    }
  }
  
  // Kick off
  updateHeight();
  
  // Interval + resize event
  setInterval(updateHeight, 500);
  target.bind('resize', updateHeight);
}