for (var i = 0; i < some_array.length; i++) {
  // Declaring this in the loop creates a one variable for
  // all instances of the loop.
  var x = some_array[i];
  closures.push(function () {
    // Do something using x.  I'll just return it.
    return x;
  });
}
// All closures now point at the last element.