Offload your images to ImageShack to save server resources.
You can either use the built-in WordPress plugin install menu, or do it the old-fashioned way:
The plugin will automatically filter the post content and replace image src attributes with ImageShack URLs.
If you want to get the URL for a specific image, you can use
get_imageshack_url($id, $size), where $id is the attachment id and $size is the desired size. Default is 'full'. If there is no URL yet, the function will return false.