Flask static_folder hosted on S3

I am trying to reroute all of my /static content to host on Amazon S3. My first thought was to use global config['path'] throughout my jinja templates, but this won't work for external css and js files, plus it is kind of messy. I found the static_folder and static_url_path released in 0.7 and this seems like what I want. However, when I go to http://localhost:8000/static/img/abc.jpg it does not locate the files on S3. Am I using this feature right or is there some other way to do this?

Thanks!