Dropkick plugin to rewrite URLs to Dropbox from local wp-content

dropkick.php

<?php
/*
 * Plugin Name: dropkick
 * Plugin URI: http://feastcraft.com/3629/solving-the-image-storage-question 
 * Description: Rewrite local image locations to dropbox locations
 * Version: 0.2
 * Author: Jonas M Luster <[email protected]>
 * Author URI: http://feastcraft.com
 * License: GPL3
 * */

$DK_MY_DROPBOX_ID = "";
$DK_MY_DROPBOX_FOLDER = "/fc-uploads/";
$DK_MY_STRIPPER = "/wp-content/uploads/";

add_filter('the_content', 'dropkickr');
add_filter('post_gallery', 'dropkickr');
add_filter('ngg_image_object', 'ngg_dropkickr_image_object');

function dropkickr($content) {
  global $wp_query;
  global $DK_MY_DROPBOX_ID; 
  global $DK_MY_DROPBOX_FOLDER;
  global $DK_MY_STRIPPER;

  $site = get_option('siteurl');
  $dropbox = "http://dl.dropbox.com/u/".$DK_MY_DROPBOX_ID.$DK_MY_DROPBOX_FOLDER;
   
  $content = preg_replace(
    '~'.$site.$DK_MY_STRIPPER.'~i',
    $dropbox,
    $content);
    
  return $content;
}

# and here we handle NextGen Images. See the comments for an explanation, this needs a little (not much) work.

function ngg_dropkickr_image_object($object)
{
  $object->thumbURL = dropkickr($object->thumbURL);
  $object->thumbnailURL = dropkickr($object->thumbnailURL);
  $object->imageURL = dropkickr($object->imageURL);
  return $object;
}