Plugin Development: WordPress processes twice on post update. How to skip process on the first?

@Steve Functions hook to save_post are always called twice, WordPress call functions hooked to save_post twice because:

• first time it saves the post revision.
• second time it saves the actual post.

NOTE: If you have disabled post revisions using define('WP_POST_REVISIONS', false); then the save_post hook will be fired only once when the actual post will be saved.

I just tested the following code and it works as expected and the echo only runs once in the something_process function.

NOTE: the way I have hooked to save_post

<?php
/*
Plugin Name: Something Amazing
Plugin URI: http://www.somewhere.com/
Description: Displays something.
Author: Some guy
Version: 1.0
Author URI: http://www.somewhere.com/
*/
function call_something() {
 return new something();
}
if (is_admin()) add_action('load-post.php','call_something');

class something {

 public function __construct() {
  add_action('add_meta_boxes',array(&$this,'something_add_boxes'));
  add_action('save_post',array(&$this,'something_process'),1,2);
 }

 public function something_add_boxes() {
  add_meta_box('something','Some Thing',array(&$this,'something_form'),'post','side','default');
 }

 public function something_form($post,$args) {
  echo '<p><input type="text" name="somethingnew" /></p>';
 }

 public function something_process($id, $post_object) {
    // don't run the echo if this is an auto save
    if ( defined('DOING_AUTOSAVE') && DOING_AUTOSAVE )
        return;

    // don't run the echo if the function is called for saving revision.
    if ( $post_object->post_type == 'revision' )
        return;

  echo 'hey there! I\'m going to cause a redirect warning, but you will see this line twice per submit!';
  //do_something_amazing();
 }
}
?>