A fork of a fork found elsewhere on the Interwebs. Major difference here from other forks is that the .blur() is removed because it causes issues with JS validation scripts.

jQuery HTML5 placeholder fix.js

// Released under MIT license: http://www.opensource.org/licenses/mit-license.php

var input = document.createElement("input");

if(('placeholder' in input) == false) { 
  $('[placeholder]')
  .each(function(){
    var i = $(this);  
    if(i.val() == '' || i.val() == i.attr('placeholder')) {
      if(this.type=='password') {
        i.addClass('password');
        this.type='text';
      }
      i.addClass('placeholder').val(i.attr('placeholder'));
    }
  })
  .focus(function() {
    var i = $(this);
    if(i.val() == i.attr('placeholder')) {
      i.val('').removeClass('placeholder');
      if(i.hasClass('password')) {
        i.removeClass('password');
        this.type='password';
      }     
    }
  })
  .blur(function() {
    var i = $(this);  
    if(i.val() == '' || i.val() == i.attr('placeholder')) {
      if(this.type=='password') {
        i.addClass('password');
        this.type='text';
      }
      i.addClass('placeholder').val(i.attr('placeholder'));
    }
  })
  .parents('form').submit(function() {
    $(this).find('[placeholder]').each(function() {
      var i = $(this);
      if(i.val() == i.attr('placeholder'))
        i.val('');
    })
  });
}