Tiny gist to mimic placeholder behaviour in old IEs. To do: remove partial jQuery dependency.

placeholderShim.js

/* Add Event Shim */
var addEvent = (function () {
   var filter = function(el, type, fn) {
      for (var i = 0, len = el.length; i < len; i++) {
         addEvent(el[i], type, fn);
      }
   };
   if (document.addEventListener) {
      return function (el, type, fn) {
         if ( el && el.nodeName || el === window ) {
            el.addEventListener(type, fn, false);
         } else if (el && el.length) {
            filter(el, type, fn);
         } 
      };
   }
 
   return function (el, type, fn) {
      if ( el && el.nodeName || el === window ) {
         el.attachEvent('on' + type, function () { return fn.call(el, window.event); });
      } else if ( el && el.length ) {
         filter(el, type, fn);
      } 
   };
})();

var fakePlaceholder = (function () {
  var placehold = {
  
    /* Set placeholder value */
    setValue: function (input) {
      
      // If placeholder is supported, do nothing.
      var test = document.createElement('input');
      if ('placeholder' in test) return false;
    
      if (input && input.length) {
        var current = "",
            value = "";

        for (var i = 0; i < input.length; i += 1) {
          var box = input.eq(i);

          current = box[0].value;
          value = box.attr('placeholder');
        
          if (!current) {
            box[0].value = value;
          }

          placehold._addEvents(box);
        }
      }
    },
  
    /* Add click and blur events */
    _addEvents: function (input) {
      addEvent(input, 'click', function () {
        if (this.value === $(this).attr('placeholder')) {
          this.value = '';
        }
      });
    
      addEvent(input, 'blur', function () {
        if (this.value === '') {
          this.value = $(this).attr('placeholder');
        }
      });
    }
  };
  
  return {
    setValue: placehold.setValue
  };
}());

/* Usage */
var input = $('input');
fakePlaceholder.setValue(input);