Javascript Array extension to find the members of a set (array) that are unique, that is they are not members of other sets. See http://goo.gl/ArHbvb.

uniqueFrom.js

/**
 * Returns a non-destructive Array of elements that are not found in
 * any of the parameter arrays.
 *
 * @param {...Array} var_args   Arrays to compare.
 */
Array.prototype.uniqueFrom = function() {
  if (!arguments.length)
    return [];
  var a1 = this.slice(0); // Start with a copy

  for (var n=0; n < arguments.length; n++) {
    var a2 = arguments[n];
    if (!(a2 instanceof Array)) throw new TypeError( 'argument ['+n+'] must be Array' );

    for(var i=0; i<a2.length; i++) {
      var index = a1.indexOf(a2[i]);
      if (index > -1) {
        a1.splice(index, 1);
      } 
    }
  }
  return a1;
}